Conductor, conductive composition and laminate

ABSTRACT

The present invention relates to a conductor having a substrate and a conductive coating film laminated on the substrate, wherein, the surface resistance value of the conductive coating film is 5×10 10 Ω/□ or less, the Ra1 of the conductive coating film is 0.7 nm or less, the Ra2 value of the conductive coating film scanning probe microscopies 0.35 nm or less, and the conductive coating film is formed with a conductive composition containing a conductive polymer (A). In addition, the present invention relates to a conductive composition which contains a conductive polymer (A) and a surfactant (B), wherein the surfactant (B) contains a specific water-soluble polymer (C), and the content of a compound (D1) with an octanol-water partition coefficient (Log Pow) of 4 or more in the conductive composition is 0.001 mass % or less, relative to the total mass of the conductive composition.

TECHNICAL FIELD

The present invention relates to a conductive composition, a conductorand a laminate.

The present invention is based upon and claims the benefit of priorityto the following Japanese Patent Applications: No. 2012-163295, filedJul. 24, 2012; No. 2012-208466, filed Sep. 21, 2012; No. 2013-088485,filed Apr. 19, 2013; and No. 2013-100736, filed May 10, 2013.

BACKGROUND ART

Patterning technologies using charged particle beams such as electronbeams and ion beams are expected as the next-generation technology toreplace photolithography.

To enhance productivity when charged particle beams are used, it isimportant to improve the sensitivity of resist. Thus, the mainstreamapproach in the technical field is to use a highly sensitive chemicallyamplified resist, in which acid is generated in the portions exposed tolight or irradiated by charged particle beams, and then to facilitatecrosslinking reactions or decomposition reactions by applying heat knownas post-exposure bake (PEB).

Also, as the patterns in semiconductor devices have become moremicroscopic in recent years, controlling resist patterns on a scale ofseveral nanometers has been required.

When patterns are formed using charged particle beams, especially on aninsulative substrate, electric fields generated by electrical charge-upin the substrate may cause the orbit of charged particle beams to becurved, and desired patterns are hard to obtain.

Therefore, to solve such a problem, a technology such as follows isknown to be effective: a conductive composition containing a conductivepolymer is applied on a resist surface to form conductive coating filmso that the resist surface is coated by the conductive film.

As for a method for forming a conductive coating film on the surface ofthe resist-layer in electron-beam lithography, coating a conductivecomposition containing a water-soluble conductive polymer and asurfactant on a resist layer (substrate) is known. For example, PatentLiterature 1 (JP2002-226721A) discloses a conductive compositioncontaining a water-soluble conductive polymer having a sulfonic acidgroup and/or a carboxyl group, a water-soluble polymer having anitrogen-containing functional group and a terminal hydrophobic groupwith a weight average molecular weight of 1000 to 1500, and a solvent.

Meanwhile, when a contaminant is contained in the above conductivecomposition, problems such as line disconnection may occur afterpatterns are formed by using electron beams. Thus, before applying on aresist layer, the conductive composition is put through microfiltrationusing a filter with a hydrophobic membrane. However, clogging occursfrequently during microfiltration of the conductive compositiondescribed in Patent Literature 1, causing problems such as replacing thefilter each time it clogs.

Also, when a conductive composition containing a conductive polymer isapplied as an antistatic agent in an electron-beam lithographic processof a semiconductor, the coating performance of the conductivecomposition and its effect on a substrate or the resist coated on thesubstrate are known to be in a tradeoff relationship.

For example, when additives such as an anionic or a cationic surfactantare added to improve the coating performance of a conductivecomposition, the acid or base derived from the surfactant adverselyaffects the resist properties, thus causing problems such as failure ofa predetermined pattern to be formed.

In addition, as an antistatic agent applicable to a next-generationprocess for semiconductor devices, a conductive composition is requiredto be capable of forming conductive coating film with surface roughnesson which even more complicated and fine patterns can be formed, namely,coating film with less surface roughness.

However, in the conductive composition described in Patent Literature 1,it has a problem that cannot use for the resist surface in anext-generation process because the surface of the conductive coatingfilm is too rough.

Also, when the conductor containing the conductive composition of PatentLiterature 1 is used for a longer period of time under a temperature of100° C. or higher, the resist laminate or the like coated on a substratetends to corrode, causing problems such as a reduction in film thicknesswhen applied on a positive resist, for example.

As described above, conventional technologies have not providedconductive compositions which exhibit excellent coating performance andsurface roughness of a conductive coating film, while showing lessimpact on the resist layer, so as to be applicable to a next-generationprocess for semiconductor devices.

In addition, as a conductive polymer capable of expressing conductivitywithout adding a doping agent, self-doped polyanilines having acidicsubstituents are known. Here, “self-doped” means that a dopant ispresent in its own structure and is capable of doping without theaddition of any doping agent.

To synthesize a self-doped polyaniline having acidic substituents, amethod is proposed to polymerize aniline having acidic substituents, forexample, aniline with a sulfonic acid group or aniline having a carboxylgroup, using an oxidizing agent in the presence of a basic reactionauxiliary.

Conventionally, a polyaniline having acidic substituents is known to behard to polymerize by itself and thus it has been difficult to produceaniline with a high-molecular-weight. However, using a polymerizationmethod conducted in the presence of a basic reaction auxiliary, ahigh-molecular-weight polymer can be produced.

Moreover, an acidic-group-substituted polyaniline obtained by the abovemethod exhibits excellent solubility in both acidic and alkalinesolutions.

However, when a polyaniline having acidic substituents is polymerizedusing an oxidizing agent in the presence of a basic reaction auxiliary,a conductive polymer is usually obtained as a reaction mixture thatcontains residual monomers as well as byproducts generated through sidereactions, such as oligomers, acidic substance (sulfate ions or thelike, which are decomposed products of monomers or oxidizing agent),basic substance (ammonium ions or the like, which are decomposedproducts of basic reaction auxiliary or oxidizing agent) and the like.Thus, the degree of purity has not always been high.

In addition, due to its molecular weight and physical properties such asstrong base properties, the basic substance cannot steadily neutralizethe acidic group of a polyaniline having acidic substituents. Thus, theacidic group site of the polyaniline having acidic substituents tends tobe subject to hydrolysis and is unstable. Accordingly, when apolyaniline having acidic substituents is coated on a resist layer andheat is applied on the coated resist layer to form a conductive coatingfilm, the acidic group tends to be easily eliminated.

In the present application, residual monomers and sulfate ions, as wellas the acidic group eliminated from a polyaniline having acidicsubstituents, are collectively referred to as “acidic substances.”

Therefore, when a polyaniline having acidic substituents is applied to achemically amplified resist, and when exposure-to-light, PEB treatmentand development are conducted while the conductive coating film(conductive film) remains on the resist layer, the acidic substances orbasic substances tend to migrate to the resist layer. As a result,deformation of patterns, variations in sensitivity or the like occur,adversely affecting the resist layer.

More specifically, if a resist layer is a positive type, when acidicsubstances migrate from the conductive coating film to the resist layer,the unexposed part of the resist layer is dissolved during development,causing a reduction in film thickness of the resist layer, narrowedpatterns, sensitivity change toward a higher sensitivity range and thelike.

On the other hand, when base substances migrate from the conductivecoating film to the resist layer, the acid component of the exposed partis deactivated, causing change in patterns, sensitivity change toward alower sensitivity range, and the like.

Also, if a resist layer is a negative type, migration of byproducts fromthe conductive coating film to the resist layer will cause an oppositeresult in each of the above.

Accordingly, to stabilize the acidic group of the polyaniline havingacidic substituents, Patent Literature 2 (JP2011-219680A), for example,proposes a method for neutralizing the acidic group site by adding abasic compound to a conductive polymer solution from which byproducts orthe like have been removed by an ion-exchange method.

According to the method described in Patent Literature 2, by adding abasic compound after byproducts or the like have been removed, the basiccompound forms salts with the acidic group of the polyaniline havingacidic substituents, thereby preventing elimination of the acidic group.Moreover, a basic compound tends to form salts through reactions withresidual monomers or sulfate ions. Thus, migration of acidic substancesfrom the conductive coating film to the resist layer is suppressed.

Furthermore, the patent literature discloses that if quaternary ammoniumcompounds such as tetramethylammonium hydroxide (TMAH) ortetraethylammonium hydroxide (TEAH) are used as a basic compound, areduction in the film thickness of a chemically amplified resist isprevented and the heat resistance of the conductive composition isenhanced.

Also, Patent Publication 3 (JP H5-171010A) discloses that a conductivepolymer solution is stabilized if a diamine compound such as urea isadded as a basic compound. Patent Publication 4 (JP2006-117925A)discloses that adding a divalent or higher aliphatic basic compound to aconductive polymer prevents a reduction in the film thickness of achemically amplified resist. Moreover, Patent Literature 5 (JP2010-116441A) discloses that adding an inorganic salt such as sodiumhydroxide enhances the heat resistance of the conductive composition.

Further, Patent Literature 6 (PCT Publication WO2012/144608) disclosesif 0.3 to 0.5 mol equivalent of tris(hydroxymethyl)aminomethane is addedto 1 mol of a unit having an acidic group among the units of aconductive polymer, the heat resistance of the conductive coating filmis improved.

However, using methods for adding a basic compound to a conductivepolymer solution described in Patent Literatures 2 to 6, migration ofacidic substances from the conductive coating film to the resist layercan be suppressed to a certain degree, but such migration needs to besuppressed even further to satisfy the level of performance required aswiring in semiconductor devices has become even finer in recent years.In addition, methods described in Patent Literatures 2 to 6 are notsufficient to suppress elimination of the acidic group from anacidic-group-substituted polyaniline.

DOCUMENTS OF RELATED ART Patent Literature

[Patent Literature 1]: JP 2002-226721A

[Patent Literature 2]: JP 2011-219680A

[Patent Literature 3]: JP H5-171010A

[Patent Literature 4]: JP 2006-117925A

[Patent Literature 5]: JP 2010-116441A

[Patent Literature 6]: PCT Publication WO2012/144608

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

Recently, as wiring in semiconductor devices has become even finer,controlling resist patterns on a scale of several nanometers has beenrequired. More specifically, adverse effects from the conductive coatingfilm on the resist are required to be reduced.

What has been in demand are conductors provided with a conductivecoating film that has less surface roughness, namely, surface roughnessapplicable to a next-generation process for semiconductor devices.

However, in conductors each provided with a conductive coating filmformed by using a conductive composition described in Patent Literatures1 to 6, a reduction in “roughness” on the surface of the conductivecoating film is not sufficient, and further improvements are necessaryto satisfy properties required in a next-generation process forsemiconductor devices.

Therefore, an aspect of the present invention is to provide a conductorcapable of preventing a reduction in the thickness of a resist layerwhile exhibiting surface roughness applicable to a next-generationprocess for semiconductor devices.

Here, “reduction in the thickness of a resist layer” indicates adverseimpact from acidic substances derived from a conductive coating film orfrom a surfactant, and is measured by film reduction testing.

Another aspect of the present invention is to provide a conductivecomposition containing a surfactant that is capable of reducing cloggingin a filter used for filtration of a conductive composition.

In addition, another aspect of the present invention is to provide aconductive composition that exhibits excellent coating performance andconductivity, lowers a reduction in the film thickness of a resistlayer, and is capable of forming a conductive coating having surfaceroughness applicable to a next-generation process for semiconductordevices.

In addition, another aspect of the present invention is to provide aconductive composition capable of forming a conductive coating film fromwhich acidic substances are less likely to migrate to the resist layer.

Solutions to the Problems

The inventors of the present invention have carried out intensivestudies and found that a conductor formed with a conductive compositionhaving the following properties is capable of solving the problemsdescribed above: namely, the conductor has a substrate and a conductivecoating film; the surface resistance value of the conductive coatingfilm is 5×10¹⁰Ω/□ or less; the surface roughness (Ra1 value) of theconductive coating film measured by a stylus profiler is at or below aspecific value; the surface roughness (Ra2 value) of the conductivecoating film measured by an optical microscope is at or below a specificvalue; and the conductive coating film is formed with a conductivecomposition that contains a specific conductive polymer (A).

Namely, a first embodiment of the present invention is a conductor has asubstrate and a conductive coating film laminated on the substrate. Thesurface resistance value of the conductive coating film is 5×10¹⁰Ω/□ orless, the surface roughness (Ra1 value) of the conductive coating filmmeasured by a stylus profiler is 0.7 nm or less, the surface roughness(Ra2 value) of the conductive coating film measured by an opticalmicroscope is 0.35 nm or less, and the conductive coating film is formedwith a conductive composition containing a conductive polymer (A).

Moreover, in the conductor according to the first embodiment of thepresent invention, the conductive polymer (A) is preferred to have anacidic group. In addition, the acidic group is preferred to be at leastone acidic group selected from the group consisting of sulfonic acidgroups and carboxyl groups.

In addition, in the conductor according to the first embodiment of thepresent invention, the conductive polymer (A) is preferred to have amonomer unit represented by the following general formula (1).

(In formula (1), R¹ to R⁴ each independently indicate a hydrogen atom, astraight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup or salt thereof. Also, an acidic group represents a sulfonic acidgroup or a carboxyl group.)

Furthermore, the inventors have found that clogging of a filter duringmicrofiltration of a conductive composition is caused when a compoundcontained in the surfactant of the conductive composition has anoctanol/water partition coefficient (Log Pow) of 4 or more.

Therefore, the inventors have carried out intensive studies and foundthat a conductive composition containing a surfactant, which was reducedthe content of a compound with an octanol/water partition coefficient(Log Pow) of 4 or more until a certain value or less, is capable ofsolving the above problem.

Namely, a conductive composition according to a second embodiment of thepresent invention contains a conductive polymer (A) and a surfactant(B), and is characterized in that the surfactant (B) contains awater-soluble polymer (C) having a nitrogen-containing functional groupand a terminal hydrophobic group; and the content of a compound (D1)with an octanol/water partition coefficient (Log Pow) of 4 or more inthe conductive composition is 0.001 mass % or less, relative to thetotal mass of the conductive composition.

In addition, the water-soluble polymer (C) is preferred to have a vinylmonomer unit having a nitrogen-containing functional group in themolecule.

Furthermore, the inventors have found that by increasing theweight-average molecular weight of a water-soluble polymer (C) having anitrogen-containing functional group and a terminal hydrophobic group,the obtained conductive composition can maintain excellent coatingproperties while decreasing adverse impact on the resist layer, and iscapable of forming a conductive coating film with surface roughnessapplicable to a next-generation process for semiconductor devices.

Namely, the conductive composition according to a third embodiment ofthe present invention is characterized in that the water-soluble polymer(C) in the surfactant (B) contained in the conductive polymer of thesecond embodiment is a water-soluble polymer (C1) having anitrogen-containing functional group and a terminal hydrophobic groupand with the weight-average molecular weight of 2000 or more.

Furthermore, the inventors have found that when a conductive compositioncontains the conductive polymer (A), two or more tertiary amines and abasic compound with a cyclic structure, that is, a conjugated structurein the molecule while having, such a conductive composition can suppressmigration of acidic substances to the resist layer.

Namely, the conductive composition according to a fourth embodiment ofthe present invention contains a conductive polymer (A1) and a basiccompound (E1), and is characterized in that the basic compound (E1) hasa conjugated structure and two or more tertiary amines in the moleculethereof.

By suppressing migration of acidic substances from the conductivecoating film to the resist layer, a reduction in the film thickness ofthe resist layer is suppressed.

Furthermore, the inventors have found that if a conductive compositioncontains a conductive polymer having an acidic group and a specificbasic compound, such a conductive composition is capable of forming aconductive coating film from which acidic substances are less likely tomigrate to the resist layer.

Namely, the conductive composition according to a fifth embodiment ofthe present invention contains a conductive polymer (A) and a basiccompound (E2), and is characterized in that the basic compound (E2) is aquaternary ammonium compound in which at least one of the four groupsbonded to a nitrogen atom is an alkyl group having 3 or more carbonatoms.

Furthermore, the conductive composition according to a sixth embodimentof the present invention contains a conductive polymer (A) and a basiccompound (E3), and is characterized by the following: the conductivepolymer (A) contains a monomer unit having an acidic group; the basiccompound (E3) has a basic group and two or more hydroxyl groups in themolecule thereof and the melting point of the basic compound (E3) is 30°C. or higher; and the content of the basic compound (E3) in theconductive composition is 0.6 to 0.8 mol, relative to 1 mol of themonomer unit having an acidic group of the conductive polymer (A).

Furthermore, a seventh embodiment of the present invention is a laminatehaving a substrate, a conductive coating film and an electron-beamresist film. In such a laminate, the electron-beam resist film islaminated on the substrate, the conductive coating film is laminated onthe electron-beam resist film, the surface resistance value of thelaminate is 5×10¹⁰Ω/□ or less, the surface roughness (Ra1 value) of theconductive coating film measured by a stylus profiler is 0.7 nm or less,the surface roughness (Ra2 value) of the conductive coating filmmeasured by an optical microscope is 0.35 nm or less, and the conductivecoating film is formed with a conductive composition containing aconductive polymer (A).

Namely, the present invention relates to the following:

[1] A conductor having a substrate and a conductive coating filmlaminated on the substrate, wherein the surface resistance value of theconductive coating film is 5×10¹⁰Ω/□ or less, the surface roughness (Ra1value) of the conductive coating film measured by a stylus profiler is0.7 nm or less, the surface roughness (Ra2 value) of the conductivecoating film measured by an optical microscope is 0.35 nm or less, andthe conductive coating film is formed with a conductive compositioncontaining a conductive polymer (A);

[2] The conductor described in [1], wherein the conductive polymer (A)has an acidic group;

[3] The conductor described in [2], wherein the acidic group is at leastone acidic group selected from the group consisting of sulfonic acidgroups and carboxyl groups;

[4] The conductor described in [1], wherein the conductive polymer (A)has a monomer unit represented by the following general formula (1);

(In formula (1), R¹ to R⁴ each independently represents a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup or salt thereof.)

[5] A conductive composition containing a conductive polymer (A) and asurfactant (B), wherein the surfactant (B) contains a water-solublepolymer (C) having a nitrogen-containing functional group and a terminalhydrophobic group, and the content of a compound (D1) with anoctanol/water partition coefficient (Log Pow) of 4 or more in theconductive composition is 0.001 mass % or less, relative to the totalmass of the conductive composition;

[6] The conductive composition described in [5], wherein thewater-soluble polymer (C) is a water-soluble polymer (C) having anitrogen-containing functional group and a terminal hydrophobic groupand with the weight-average molecular weight of 2000 or more;

[7] The conductive composition described in [6], wherein thewater-soluble polymer (C) contains a vinyl monomer unit having anitrogen-containing functional group in the molecule;

[8] The conductive composition described in [5], wherein the conductivepolymer (A) has a monomer unit represented by the following generalformula (1);

(In formula (1), R¹ to R⁴ each independently represents a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup or salt thereof.)

[9] The conductive composition described in [5], wherein the conductivepolymer (A) contains at least one acidic group selected from the groupconsisting of sulfonic acid groups and carboxyl groups;

[10] A conductive composition containing a conductive polymer (A1) and abasic compound (E1), wherein the basic compound (E1) has a conjugatedstructure and two or more tertiary amines in the molecule;

[11] The conductive composition described in [10], wherein theconductive polymer (A1) has a monomer unit represented by the followinggeneral formula (1);

(In formula (1), R¹ to R⁴ each independently represents a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup or salt thereof.)

[12] The conductive composition described in [10], wherein theconductive polymer (A1) contains at least one acidic group selected fromthe group consisting of sulfonic acid groups and carboxyl groups;

[13] A conductive composition containing a conductive polymer (A) and abasic compound (E2), wherein the basic compound (E2) is a quaternaryammonium compound in which at least one of the four groups bonded to anitrogen atom is an alkyl group having 3 or more carbon atoms;

[14] The conductive composition described in [13], wherein theconductive polymer (A) has a monomer unit represented by the followinggeneral formula (1);

(In formula (1), R¹ to R⁴ each independently represents a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup or salt thereof.)

[15] The conductive composition described in [13], wherein theconductive polymer (A) contains at least one acidic group selected fromthe group consisting of sulfonic acid groups and carboxyl groups;

[16] A conductive composition containing a conductive polymer (A) and abasic compound (E3), wherein the conductive polymer (A) contains amonomer unit having an acidic group, the basic compound (E3) has a basicgroup and two or more hydroxyl groups in the molecule, the melting pointof the basic compound (E3) is 30° C. or more, and the content of thebasic compound (E3) in the conductive composition is 0.6 to 0.8 molrelative to 1 mol of the monomer unit having an acidic group of theconductive polymer (A);

[17] The conductive composition described in [16], wherein the monomerunit having an acidic group of the conductive polymer (A) is representedby the following general formula (1) w;

(In formula (1), R¹ to R⁴ each independently represent a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup or salt thereof.)

[18] The conductive composition described in [16], wherein the acidicgroup is at least one acidic group selected from the group consisting ofsulfonic acid groups and carboxyl groups;

[19] The conductive composition described in any one of [10] to [18],further containing a surfactant (B);

[20] The conductive composition described in [19], wherein thesurfactant (B) contains a water-soluble polymer (C) having anitrogen-containing functional group and a terminal hydrophobic group,and the content of a compound (D1) with an octanol/water partitioncoefficient (Log Pow) of 4 or more in the conductive composition is0.001 mass % or less, relative to the total mass of the conductivecomposition; and

[21] A laminate having a substrate, a conductive coating film and anelectron-beam resist film, wherein the electron-beam resist film islaminated at least on one surface of the substrate, the conductivecoating film is laminated on the electron-beam resist film, the surfaceresistance value of the conductive coating film is 5×10¹⁰Ω/□ or less,the surface roughness (Ra1 value) of the conductive coating filmmeasured by a stylus profiler is 0.7 nm or less, the surface roughness(Ra2 value) of the conductive coating film measured by an opticalmicroscope is 0.35 nm or less, and the conductive coating film is formedwith a conductive composition containing a conductive polymer (A).

Effects of the Invention

A conductor according to the first embodiment of the present inventionis applicable to a next-generation process for semiconductor devices,since a reduction in the film thickness of the resist layer is smallwhen such a conductor is used.

The conductive composition according to the second embodiment of thepresent invention exhibits excellent performance when passing throughhydrophobic membranes during the filtration process, and thus thefrequency of replacing filters is reduced.

In addition, the conductive composition according to the thirdembodiment of the present invention exhibits excellent coatingperformance and conductivity. When such a conductive composition is usedfor forming a conductive coating film, a reduction in the film thicknessof the laminate such as a resist coated on a substrate is smallregardless of conditions of its environment such as temperature, and thecoating film shows less surface roughness, namely, surface roughnessapplicable to a next-generation process for semiconductor devices. Thus,it is very useful in industrial applications.

In addition, the conductive composition according to the thirdembodiment of the present invention is capable of forming a conductorhaving an insoluble or removable soluble conductive coating film(conductive polymer film) by applying heat after the conductor isformed.

Accordingly, the conductive composition is applicable to forming apermanent anti-static film as well as a temporary anti-static film usedduring the production process.

Furthermore, the conductive composition according to the fourthembodiment of the present invention is capable of suppressing areduction in the film thickness of the resist layer by controllingmigration of acidic substances from the conductive coating film to theresist layer.

Conductive compositions according to the fifth and sixth embodiments ofthe present invention are capable of forming conductive coating filmsfrom which acidic substances are less likely to migrate to the resistlayer.

In addition, conductive coating films obtained by using conductivecompositions of the fifth and six embodiments of the present inventionare capable of reducing or suppressing migration of acidic substances tothe resist layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing an example of the conductorrelated to the present invention; and

FIG. 2 is a cross-sectional view showing an example of the laminaterelated to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, the embodiments of the present invention are describedin detail.

In the present application, “conductivity” indicates having a surfaceresistance value of 5.0×10¹⁰Ω/□ or less.

In addition, “dissolubility” in the present application indicates thatat least 0.1 gram of a substance is homogeneously dissolved in 10 grams(liquid temperature of 25° C.) of water, water containing a base and/ora basic salt, water containing acid, or a mixture of water and awater-soluble organic solvent.

Also, “water-soluble” in the present application indicates dissolubilityin water in relation to the “dissolubility” defined above.

<Conductor>

First, a conductor according to the first embodiment of the presentinvention is described.

A conductor of the first embodiment has a substrate and a conductivecoating film laminated on the substrate. The conductor is characterizedby the following: the surface resistance value of the conductive coatingfilm is 5×10¹⁰Ω/□ or less; the surface roughness (Ra1 value) of theconductive coating film measured by a stylus profiler is 0.7 nm or less;the surface roughness (Ra2 value) of the conductive coating filmmeasured by an optical microscope is 0.35 nm or less; and the conductivecoating film is formed with a conductive composition containing aconductive polymer (A).

FIG. 1 is a cross-sectional view showing one example of the conductor asthe first embodiment. The Conductor 10 in this example is structured bylaminating the conductive coating film 12 on the substrate 11.

In FIG. 1, the measurement ratio is different from the actual ratio forthe convenience of description.

In the conductor of the first embodiment, a conductive polymer (A) ispreferred to have an acidic group.

The acidic group is preferred to be at least one acidic group selectedfrom the group consisting of sulfonic acid groups and carboxyl groups.

In addition, the conductive polymer (A) is preferred to have a monomerunit represented by the following general formula (1).

(In formula (1), R¹ to R⁴ each independently represent a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup or salt thereof.)

The surface resistance value of the conductive coating film of the firstembodiment can be measured by using a surface resistivity meter.

The surface roughness (Ra1 value) of the conductive coating filmindicates the value measured by a stylus profiler (instrument formeasuring profile, surface roughness, and microscopic shapes).

In addition, the surface roughness (Ra2 value) of the conductive coatingfilm indicates the value measured by an optical microscope.

In the first embodiment of the present invention, the surface roughness(Ra1 value) of the conductive coating film is preferred to be 0.7 nm orless, more preferably 0.6 nm or less. In addition, the lower limit ofthe surface roughness (Ra1 value) is not limited specifically as long asthe effects of the present invention are achieved. However, it ispreferred to be 0.3 nm or more from the viewpoint of reliability of themeasurement value. Namely, in the conductor according to the firstembodiment of the present invention, the surface roughness (Ra1 value)is preferred to be 0.3 to 0.7 nm, more preferably 0.3 to 0.6 nm. Thesurface roughness (Ra1 value) of the conductive coating film ispreferred to be within the above range, since the deposit ofaforementioned compound (D1) is suppressed.

Moreover, in the first embodiment of the present invention, the surfaceroughness (Ra2 value) of the conductive coating film is preferred to be0.35 nm or less, preferably 0.33 nm or less. In addition, the lowerlimit of the surface roughness (Ra2 value) is not limited specificallyas long as the effects of the present invention are achieved. However,it is preferred to be 0.1 nm or more from the viewpoint of obtainingsurface roughness of a wafer (substrate). Namely, in the conductoraccording to the first embodiment, the surface roughness (Ra2 value) ispreferred to be 0.1 to 0.35 nm, more preferably 0.1 to 0.33 nm. Thesurface roughness (Ra2 value) of the conductive coating film ispreferred to be within the above range, since roughness caused by saltsformed by the conductive polymer and basic substances is suppressed.

(Conductive Polymer (A))

The conductor according to the first embodiment of the present inventionis made of a conductive composition containing a conductive polymer (A).A conductive polymer (A) is preferred to have an acidic group. Examplesof an acidic group are phosphate groups, sulfonic acid groups andcarboxyl groups. Among those, the acidic group is preferred to be atleast one acidic group selected from the group consisting of sulfonicacid groups and carboxyl groups from the viewpoint of processability.

As for a conductive polymer (A) having at least one acidic groupselected from the group consisting of sulfonic acid groups and carboxylgroups, it is not limited specifically as long as the effects of thepresent invention are achieved. Any known conductive polymers may beused.

From the viewpoint of dissolubility, examples of such a conductivepolymer are preferred to be those in JP S61-197633A, JP S63-39916A, JPH1-301714A, JP H5-504153A, JP H5-503953A, JP H4-32848A, JP H4-328181A,JP H6-145386A, JP H6-56987A, JP H5-226238A, JP H5-178989A, JPH6-293828A, JP H7-118524A, JP H6-32845A, JP H6-87949A, JP H6-256516A, JPH7-41756A, JP H7-48436A, and JP H4-268331A.

More specifically, examples of a conductive polymer (A) are t-conjugatedconductive polymers containing, as a monomer unit, at least one typeselected from the group consisting of phenylenevinylene, vinylene,thienylene, pyrrolylene, phenylene, iminophenylene, isothianaphthene,furylene, and carbazolylene in which their respective α-position orβ-position is substituted by at least one acidic group selected from thegroup consisting of sulfonic acid groups and carboxyl groups.

When a π-conjugated conductive polymer contains at least one type of amonomer unit selected from the group consisting of iminophenylenes andcarbazolylenes, examples of a conductive polymer are those having thefollowing alkyl group on a nitrogen atom of the monomer unit: an alkylgroup having at least one group selected from the group consisting ofsulfonic acid groups and carboxyl groups; an alkyl group substitutedwith at least a group selected from the group consisting of sulfonicacid groups and carboxyl groups; or an alkyl group containing an etherbond.

Among the above, from the viewpoints of conductivity and dissolubility,it is preferred to use a conductive polymer (A) that contains at leastone type selected from the group consisting of thienylene, pyrrolylene,iminophenylene, phenylenevinylene, carbazolylene and isothianaphthene asthe monomer unit, whose n-position is substituted with at least a groupselected from the group consisting of sulfonic acid groups and carboxylgroups.

Also, from the viewpoints of conductivity and dissolubility, aconductive polymer (A) is preferred to contain a polythiophene skeleton,polypyrrol skeleton, polyaniline skeleton, polyphenylenevinyleneskeleton, or polyisothianaphthene skeleton. It is especially preferredif a conductive polymer (A) contains at least one type of a monomer unitselected from the group consisting of those represented by the followinggeneral formulas (2) to (4) at 20 to 100 mol % based on the total numberof monomer units of the entire conductive polymer (A).

In general formulas (2) to (4) above, X indicates a sulfur atom or anitrogen atom, R⁵ to R¹⁵ each independently indicates a hydrogen atom ora group selected from the group consisting of —SO₃H, —R¹⁶SO₃H, —OCH₃,—CH₃, —C₂H₅, —F, —Cl, —Br, —I, —N(R¹⁷)₂, —NHCOR¹⁷, —OH, —O—, —SR¹⁷,—OR¹⁷, —OCOR¹⁷, —NO₂, —COOH, —R¹⁶COOH, —COOR¹⁷, —COR¹⁷, —CHO and —CN.Here, R¹⁶ indicates an alkylene group, an arylene group, or anaralkylene group having 1 to 24 carbon atoms, and R¹⁷ indicates an alkylgroup, aryl group or aralkyl group.

However, at least one each of R⁵ to R⁶ of general formula (2), R⁷ to R¹⁰of general formula (3) and R¹¹ to R¹⁵ of general formula (4) is a groupselected from the group consisting of —SO₃H, —R¹⁶SO₃H, —COOH, —R¹⁶COOH,or their alkali metal salts, ammonium salts and substituted ammoniumsalts.

Examples of alkali metal salts are lithium salts, sodium salts,potassium salts and the like.

More specifically, alkali metal salts are, for example, lithium sulfate,lithium carbonate, lithium hydroxide, sodium sulfate, sodium carbonate,sodium hydroxide, potassium sulfate, potassium carbonate, potassiumhydroxide and derivatives with their skeletons.

Examples of substituted ammonium salts are aliphatic ammonium salts,saturated alicyclic ammonium salts, unsaturated alicyclic ammonium saltsand the like.

An example of aliphatic ammonium salt is ammonium represented by thefollowing general formula (III).

Specific examples of an aliphatic ammonium represented by generalformula (III) above are: methylammonium, dimethylammonium,trimethylammonium, ethylammonium, diethylammonium, triethylammonium,methylethylammonium, diethylmethylammonium, dimethylethylammonium,propyl ammonium, dipropylammonium, isopropyl ammonium, diisopropylammonium, butyl ammonium, dibutylammonium, methylpropylammonium,ethylpropylammonium, methylisopropylammonium, ethylisopropylammonium,methylbutylammonium, ethylbutyl ammonium, tetramethylammonium,tetramethylolammonium, tetraethyl ammonium, tetra-t-butyl ammonium,tetra-sec-butyl ammonium, and tetra-t-butylammonium. Among those, atleast any one of R^(5A) to R^(8A) is preferred to be a hydrogen atom,and the rest are each preferred to be an alkyl group having 1 to 4carbon atoms. It is more preferred if any two of R^(5A) to R^(8A) areeach a hydrogen atom, and the rest are each an alkyl group having 1 to 4carbon atoms.

Examples of saturated alicyclic ammonium salts are piperidinium,pyrrolidinium, morpholinium, piperazinium and derivatives with theirskeletons.

Examples of unsaturated alicyclic ammonium salts are pyridinium,α-picolinium, β-picolinium, γ-picolinium, quinolinium, isoquinolinium,pyrrolinium, and derivatives with their skeletons.

In the conductive composition to form a conductor of the firstembodiment, a conductive polymer (A) is preferred to further contain amonomer unit represented by the following general formula (1).

(In formula (1), R¹ to R⁴ each independently represent a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup or salt thereof. Here, an acidic group means a sulfonic acid groupor a carboxyl group.)

Here, a sulfonic acid group and a carboxyl group may be contained in theform of acid (—SO₃H, —COOH), or may be contained as ions (—SO₃ ⁻,—COO⁻).

In addition, “salt” indicates at least one type of alkali metal salts,alkaline earth metal salts, ammonium salts and saturated ammonium salts.

Alkali metal salts and substituted ammonium salts may be the same asthose described above.

Examples of alkaline earth metal salts are magnesium salts and calciumsalts.

Examples of saturated ammonium salts are aliphatic ammonium salts,saturated alicyclic ammonium salts and unsaturated alicyclic ammoniumsalts.

As a monomer unit represented by general formula (1) above, it ispreferred from the viewpoint of processability that any one of R¹ to R⁴be a straight-chain or branched-chain alkoxyl group having 1 to 4 carbonatoms, any of the rest be a sulfonic acid group and the rest behydrogen.

The conductive polymer (A) is preferred to contain a monomer unitrepresented by general formula (1) above at 10 to 100 mol %, morepreferably 50 to 100 mol %, based on 100 mol % of all monomer unitscomposed of the conductive polymer (A). It is especially preferable tobe 100 mol %, because excellent dissolubility in water and organicsolvents is achieved regardless of its pH.

Also, the conductive polymer (A) is preferred to contain a monomer unitrepresented by general formula (1) at 10 or more in the molecule,namely, at 10 mol % or more, because excellent conductivity is achievedat such content.

The conductive polymer (A) in the first embodiment of the presentinvention (hereinafter may also be referred to as a water-solubleaniline-based conductive polymer) is preferred to be contained at 70% ormore, more preferably at 80% or more, especially preferably at 90% ormore, considering the content of the acidic group relative to the totalnumber of a monomer unit represented by general formula (1), namely, thetotal number of aromatic rings, as well as from the viewpoint ofenhancing solubility.

In another aspect of the first embodiment of the present invention, thecontent of a sulfonic acid group or a carboxyl group relative to thetotal number of aromatic rings in the conductive polymer (A) ispreferred to be 50% or more, more preferably 70% or more, especiallypreferably 90% or more, and most preferably 100%. A content of 50% ormore in the conductive polymer (A) is preferable since the dissolubilityimproves significantly.

The above content can be calculated from the ratio of monomers suppliedwhen the conductive polymer is produced.

Also, in the conductive polymer (A), the acidic group other than asulfonic acid group or a carboxyl group on the aromatic ring of amonomer unit is preferred to be an electron-donating group from theviewpoint of reactivity of the monomer. In particular, it is preferredto be an alkyl group having 1 to 24 carbon atoms, an alkoxyl grouphaving 1 to 24 carbon atoms, a halogen group (—F, —Cl, —Br or I), or thelike. Among those, an alkoxyl group having 1 to 24 carbon atoms is morepreferred from the viewpoint of electron-donating properties.

In addition, as long as solubility, conductivity and other propertiesare not affected, monomer units of the conductive polymer (A) except forthe unit represented by the general formula (1) may include at least onetype of a monomer unit selected from the group consisting of substitutedor unsubstituted anilines, thiophenes, pyrroles, phenylenes, vinylenes,and other divalent unsaturated or divalent saturated groups. Examples ofsubstituted groups are acidic groups, alkyl groups, alkoxyl groups andhalogen groups.

Moreover, the conductive polymer (A) is preferred to be a compound witha structure represented by the following general formula (5).

In general formula (5), R¹⁸ to R³³ are each independently selected fromthe group consisting of a hydrogen atom, a straight-chain orbranched-chain alkyl group having 1 to 24 carbon atoms, a straight-chainor branched-chain alkoxyl group having 1 to 24 carbon atoms, an acidicgroup, a hydroxyl group, a nitro group and a halogen atom. At least oneof R¹⁸ to R³³ is an acidic group. Also, “n” indicates the degree ofpolymerization. In the first embodiment of the present invention, “n” ispreferred to be a whole number of 5 to 2500.

Among the compounds with the structure represented by the generalformula (5), poly(2-sulfo-5-methoxy-1,4-iminophenylene) is especiallypreferred because of its excellent dissolubility.

The weight average molecular weight of the conductive polymer (A) ispreferred to be 3,000 to 1,000,000, more preferably 3,000 to 50,000. Ifthe weight average molecular weight of a conductive polymer is 3,000 ormore, conductivity, film-forming performance and film strength areexcellent. On the other hand, if the weight average molecular weight ofa conductive polymer is 1,000,000 or less, dissolubility in solvents isexcellent.

The weight average molecular weight (in terms of sodium polystyrenesulfonate) of a conductive polymer is measured by gel permeationchromatography (GPC).

In another aspect, the weight average molecular weight of the conductivepolymer (A) is preferred to be 3,000 to 1,000,000, more preferably 5,000to 80,000, especially preferably 10,000 to 70,000, from the viewpoint ofconductivity.

In another aspect, at least one part of the acidic group contained inthe conductive polymer (A) of the present invention is preferred to be afree acid type from the viewpoint of improving conductivity.

In another aspect of the present invention, the weight average molecularweight of a conductive polymer (A) in terms of sodium polystyrenesulfonate measured by gel permeation chromatography (hereinafterreferred to as GPC) is preferred to be 2,000 to 1,000,000, morepreferably 3,000 to 800,000, even more preferably 5,000 to 500,000,especially preferably 10,000 to 100,000, from the viewpoints ofconductivity, dissolubility and film-forming performance.

If the weight average molecular weight of the conductive polymer (A) isless than 2,000, excellent dissolubility is obtained, but conductivityand film-forming performance may be insufficient.

On the other hand, if the weight average molecular weight is greaterthan 1,000,000, excellent conductivity is obtained, but dissolubilitymay be insufficient.

Here, “film-forming performance” indicates the composition is capable offorming uniform film that does not repel or the like, and suchperformance is evaluated by a spin-coating method on glass or the like.More specifically, a conductive composition is coated on glass by spincoating, and the result is evaluated visually or by using a microscopeor the like.

(Method for Producing Conductive Polymer (A))

In the first embodiment of the present invention, a conductive polymer(A) described above is produced using a known method. It is not limitedto any method as long as the effects of the present invention areachieved.

A specific example is, for example, a method for polymerizing apolymerizable monomer containing the monomer unit above by varioussynthesizing methods such as chemical oxidation and electrolyticoxidation. For example, synthesizing methods described in JP H7-196791A,JP H7-324132A and the like proposed by the inventors of the presentinvention may be employed.

As described above, a conductive polymer (A) is produced by a knownmethod. More specifically, such a method includes a step forpolymerizing at least one type of a compound (monomer) selected from thegroup consisting of anilines having acidic substituents, their alkalimetal salts, ammonium salts and substituted ammonium salts using anoxidizing agent in the presence of a basic reaction auxiliary.

An example of anilines having acidic substituents is an anilinesubstituted by sulfonic acid which has sulfonic acid as an acidic group.

Typical anilines substituted by sulfonate are aminobenzenesulfonicacids; in particular, o-, m- and p-aminobenzensulfonic acids,aniline-2,6-disulfonic acid, aniline-2,5-disulfonic acid,aniline-3,5-disulfonic acid, aniline-2,4-disulfonic acid,aniline-3,4-disulfonic acid and the like are preferred.

Other than aminobenzenesulfonic acids, anilines substituted by sulfonateare, for example, alkyl-group-substituted aminobenzenesulfonic acidssuch as methylaminobenzenesulfonic acid, ethylaminobenzenesulfonic acid,n-propyl aminobenzenesulfonic acid, isopropyl-aminobenzenesulfonic acid,n-butylaminobenzenesulfonic acid, sec-butyl aminobenzenesulfonic acid,and t-butyl aminobenzenesulfonic acid; aminobenzenesulfonic acidssubstituted by alkoxyl group such as methoxyaminobenzenesulfonic acid,ethoxyaminobenzenesulfonic acid, and propoxyaminobenzenesulfonic acid;aminobenzenesulfonic acids substituted by hydroxyl group;aminobenzenesulfonic acids substituted by nitro group; andaminobenzenesulfonic acids substituted by halogen such asfluoroaminobenzenesulfonic acid, chloroaminobenzenesulfonic acid, andbromoaminobenzenesulfonic acid.

Among those, because a conductive polymer (A) with especially excellentconductivity and dissolubility is obtained, aminobenzenesulfonic acidssubstituted by alkyl-group, aminobenzenesulfonic acids substituted byalkoxyl group, aminobenzenesulfonic acids substituted by hydroxyl group,or aminobenzenesulfonic acids substituted by halogen are preferred.Also, aminobenzenesulfonic acids substituted by alkoxyl group, theiralkali metal salts, ammonium salts and substituted ammonium salts areespecially preferred from the viewpoint of processability.

Those anilines substituted by sulfonic acid may be used alone or incombination of two or more in any proportion.

Examples of a basic reaction auxiliary used for producing a conductivepolymer (A) are inorganic bases, ammonia, aliphatic amines, cyclicsaturated amines, cyclic unsaturated amines and the like.

Examples of basic reaction auxiliaries are preferred to be inorganicbases, more specifically, sodium hydroxides, potassium hydroxides,lithium hydroxides and the like.

Examples of basic reaction auxiliaries other than inorganic bases arealiphatic amines such as methylamine, dimethylamine, trimethylamine,ethylamine, diethylamine, triethylamine, ethylmethylamine,ethyldimethylamine, diethylmethyl amine and the like; and cyclicunsaturated amines such as pyridine, α-picoline, β-picoline, γ-picolineand the like.

Those basic reaction auxiliaries may be used alone or in combination oftwo or more in any proportion.

As for the content of such a basic reaction auxiliary to be added, it ispreferred to be 0.01 to 100 times at the weight ratio, relative to theweight of the monomer, and is more preferred to be 0.1 to 10 times.

An oxidizing agent used for producing a conductive polymer (A) is notlimited specifically as long as its standard electrode potential is 0.6V or more. For example, peroxodisulfuric acids such as ammoniumperoxodisulfate, sodium peroxodipersulfate, potassium peroxodisulfateand hydrogen peroxide are preferred to be used.

Those oxidizing agents may be used alone or in combination of two ormore in any proportion.

The content of an oxidizing agent to be added is preferred to be 1 molto 5 mol, more preferably 1 mol to 3 mol, based on 1 mol of the monomerabove.

Examples of methods for polymerizing a conductive polymer (A) are:dropping a mixed solution of a monomer and a basic reaction auxiliaryinto an oxidizing agent solution; dropping an oxidizing agent solutioninto a mixed solution of a monomer and a basic reaction auxiliary; anddropping an oxidizing agent solution and a mixed solution of a monomerand a basic reaction auxiliary into a reaction vessel or the like at thesame time.

After the polymerization process, the solvent is filtrated by afiltration instrument such as a centrifugal separator. Moreover, thepolymer filtrate is cleansed, if needed, by alcohols such as methylalcohol and ethyl alcohol, acetone, acetonitrile or the like, and driedto obtain a polymer (conductive polymer (A)).

(Conductive Composition)

In a conductor according to the first embodiment of the presentinvention, the conductive composition that forms a conductive coatingfilm is preferred to be any of the conductive compositions according tothe later-described second through sixth embodiments of the presentinvention.

(Method for Producing Conductor of the First Embodiment)

A conductor according to the first embodiment of the present inventionis produced when a conductive coating film is formed on at least onesurface of a substrate by coating a conductive composition containing aconductive polymer (A) and by drying the composition, and then the filmis kept at normal temperature (25° C.) for 1 to 60 minutes or heattreatment is performed on the film.

In the case of performing the heat treatment, the temperature for theheat treatment is preferred to be in a range of 40° C. to 250° C., morepreferably in a range of 60° C. to 200° C., from the viewpoint ofconductivity. The treatment time is preferred to be within one hour,more preferably within 30 minutes, from the viewpoint of stability.Methods for applying the conductive composition on a substrate are notlimited specifically as long as the effects of the present invention areachieved; for example, spin coating, spray coating, dip coating, rollcoating, gravure coating, reverse coating, roll brushing, air knifecoating, curtain coating methods and the like are used.

The film thickness of the conductive coating film obtained by applyingthe conductive composition is preferred to be 1 to 100 nm, morepreferably 3 to 70 nm, especially preferably 5 to 40 nm. The filmthickness can be measured using a stylus profiler (instrument formeasuring profile, surface roughness, and microscopic shapes).

As for a substrate, it is not limited specifically as long as theeffects of the present invention are achieved. Examples of a substrateare polyester resins such as PET and PBT, polyolefin resins representedby polyethylene and polypropylene, vinyl chloride, nylon, polystyrene,polycarbonate, epoxy resin, fluororesin, polysulfone, polyimide,polyurethane, phenolic resin, silicone resin, molded products of variouspolymer compounds such as synthetic paper, film, paper, iron, glass,fused quartz, various wafers, aluminum, copper, zinc, nickel andstainless steel; and products on which various coating materials,photosensitive resin, resist or the like are coated on the materialslisted above.

The thickness of a substrate is not limited specifically as long as theeffects of the present invention are achieved; however, the thickness ispreferred to be 1 μm to 2 cm, more preferably 10 μm to 1 cm.

A step for applying a conductive composition to the substrate above maybe employed before or during the process for manufacturing thesubstrate, for example, uniaxial stretching, biaxial stretching, moldingor embossing. Alternatively, a step for applying the composition to thesubstrate may be employed after those processing steps are completed.

Also, a conductive coating film may be formed by applying the conductivecomposition on top of substrates listed above, on which one of variouscoating materials or photosensitive materials is already coated.

Second Embodiment Conductive Composition

Next, a conductive composition according to the second embodiment of thepresent invention is described.

The conductive composition of the second embodiment contains aconductive polymer (A) and a surfactant (B), and is characterized by thefollowing: the surfactant (B) contains a water-soluble polymer (C)having a nitrogen-containing functional group and a terminal hydrophobicgroup; and the content of a compound (D1) with an octanol/waterpartition coefficient (Log Pow) of 4 or more in the conductivecomposition is 0.001 mass % or less, relative to the total mass of theconductive composition.

In addition, a conductive polymer (A) is preferred to have a monomerunit represented by the following general formula (1).

(In formula (1), R¹ to R⁴ each independently represents a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup or salt thereof.)

In addition, the conductive polymer (A) is preferred to have at leastone acidic group selected from the group consisting of sulfonic acidgroups and carboxyl groups.

Furthermore, the second embodiment of the present invention has thefollowing aspects.

An aspect of the second embodiment is a surfactant composition, whichcontains, as a surfactant, a water-soluble polymer having anitrogen-containing functional group and a terminal hydrophobic groupand may optionally contain a compound (D1) with an octanol/waterpartition coefficient (Log Pow) of 4 or more. Here, the content of acompound (D1) with an octanol/water partition coefficient (Log Pow) of 4or more is 1 part by mass or less based on 100 parts by mass of thewater-soluble polymer.

Another aspect of the second embodiment is a method for producing thesurfactant composition: in the method, an adsorbent makes contact with amixture containing a water-soluble polymer having a nitrogen-containingfunctional group and a terminal hydrophobic group and a compound (D1)with an octanol/water partition coefficient (Log Pow) of 4 or more so asto decrease the compound (D1) with an octanol/water partitioncoefficient (Log Pow) of 4 or more.

Another aspect of the second embodiment is a conductive compositioncontaining the surfactant composition above and a water-solubleconductive polymer. Another aspect of the second embodiment is a methodfor forming a conductive coating film by applying the conductivecomposition on a substrate after the composition is filtrated through afilter.

In another aspect of the second embodiment of the present invention, thesurfactant composition contains a water-soluble polymer (hereinafterreferred to as a “surfactant”) having a nitrogen-containing functionalgroup and a terminal hydrophobic group, and may optionally contain acompound (D1) with an octanol/water partition coefficient (Log Pow) of 4or more. The content of a compound (D1) with an octanol/water partitioncoefficient (Log Pow) of 4 or more is 1 part by mass or less based on100 parts by mass of the surfactant.

(Compound (D1))

In the second embodiment of the present invention, Log Pow indicates theratio of concentrations of the compound in octanol and in waterrespectively when a subject compound is dissolved in a mixture ofoctanol and water (at any given mixing ratio). In the presentspecification, Log Pow is a value calculated by using Chem Draw Pro 12.0made by Cambridge Soft In addition, the content of a compound (D1) withan octanol/water partition coefficient (Log Pow) of 4 or more ismeasured by an internal standard method using gas chromatography and isindicated by the value in terms of n-dodecyl mercaptan. Namely, a samplewas measured by a gas chromatograph under the following conditions. Thecolumn was retained at a temperature of 40° C. for 1 minute. Next, thetemperature was raised from 40° C. to 60° C. (time for raising thetemperature was 5 minutes). After the column temperature was held at 60°C. for 1 minute, the temperature was further raised from 60° C. to 230°C. (time for raising the temperature was 30 minutes) and the column washeld at 230° C. for 10 minutes. The flow rate of the carrier was 4.1mL/min. The content was obtained from a peak, when the retention timewas 36 minutes.

In the second embodiment of the present invention, the content of acompound (D1) with an octanol/water partition coefficient (Log Pow) of 4or more in a conductive composition is 0.001 mass % or less relative tothe total mass of the conductive composition. In addition, the contentof a compound (D1) in a surfactant (B) is 1 part by mass or less basedon 100 parts by mass of the surfactant (B), that is, the content of acompound (D1) in the surfactant (B) is 1 mass % or less relative to thetotal mass of the surfactant (B). Namely, by setting the content of acompound (D1) to be n 0.001 mass % or less relative to the total mass ofthe conductive composition, or by setting the content of a compound (D1)to be 1 mass % or less relative to the total mass of the surfactant (B),the filtration performance of the conductive composition duringmicrofiltration is enhanced. In addition, the content of a compound (D1)in the conductive composition is preferred to be set at 0 to 0.001 mass%, especially preferable at 0 mass %, relative to the total mass of theconductive composition. Also, the content of a compound (D1) to thetotal mass of the surfactant (B) is more preferred to be set at 0.05mass % or less, especially preferable at 0 mass %, of the total mass ofthe conductive composition. A compound (D1) indicates such a compoundwith an octanol/water partition coefficient (Log Pow) of 4 to 10. In thesecond embodiment of the present invention, a compound (D1) with anoctanol/water partition coefficient (Log Pow) of 4 or more is notlimited specifically, as long as the compound has a Log Pow of 4 ormore. Examples of a compound (D1) includes chain transfer agents,polymerization initiators used for producing a later-describedwater-soluble polymer (C), or byproducts of such agents.

For example, during the process for producing a water-soluble polymer(C), when 2,2′-azobis(2-methylbutyronitrile) as a polymerizationinitiator and n-dodecyl mercaptan as a chain transfer agent are used,their reaction product, 2-(dodecylthio)-2-methylbutyronitrile (Log Powof 6.5), is included as a compound (D1). Also, when 2,2′-azobisisobutyronitrile as a polymerization initiator and n-octyl mercaptan asa chain transfer agent are used, their reaction product,2-(octylthio)-2-methylpropanenitrile (Log Pow of 4.4), is included as acompound (D1).

(Surfactant (B))

In the second embodiment of the present invention, a surfactant (B)contains a water-soluble polymer (C) having a nitrogen-containingfunctional group and a terminal hydrophobic group. Such a water-solublepolymer (C) is produced by introducing a hydrophobic group at a terminalof a water-soluble polymer having a nitrogen-containing functionalgroup, for example.

In particular, “a terminal of a water-soluble polymer” indicates a sitebetween a main-chain end to the polymer end. Namely, a water-solublepolymer (C) indicates such a polymer that has a monomer unit having anitrogen-containing functional group as a main-chain structure whilehaving a hydrophobic group at a site between the main-chain end and thepolymer end. “Main-chain structure” indicates a monomer unit having anitrogen-containing functional group except for monomer units derivedfrom the terminal hydrophobic group.

(Water-Soluble Polymer (C))

A surfactant (B) containing such a water-soluble polymer (C) exhibitssurface activity by the hydrophilic group (site of main-chain structure)and by the terminal hydrophobic group of the water-soluble polymer (C).Examples of a terminal hydrophobic group are those containing at leastone type selected from the group consisting of alkyl groups, aralkylgroups and aryl groups having 3 to 100 carbon atoms, more preferably 5to 50 carbon atoms, especially preferably 7 to 30 carbon atoms. Specificexamples of a terminal hydrophobic group are alkyl groups, aralkylgroups, aryl groups, alkoxyl groups, aralkyloxy groups, aryloxy groups,alkylthio groups, aralkylthio groups and arylthio groups each having 3to 100 carbon atoms, primary or secondary alkylamino groups,aralkylamino groups and arylamino groups. Alkylthio groups, aralkylthiogroups and arylthio groups each having 5 to 50 carbon atoms arepreferred. Specific examples are n-octyl mercaptan, n-dodecyl mercaptanand the like.

In the second embodiment of the present invention, the content of awater-soluble polymer (C) in the surfactant (B) is preferred to be 99 to100 mass %, more preferably 99.9 to 100 mass %, relative to the totalmass of the surfactant (B). Also, in the second embodiment, it is mostpreferred if the surfactant (B) is composed only of a water-solublepolymer (C).

The terminal hydrophobic group of a water-soluble polymer (C) may beintroduced to the water-soluble polymer (C) by any method as long as theeffects of the present invention are achieved. Usually, selecting achain transfer agent used for a vinyl polymerization is preferredbecause of its easy process.

An example of a chain transfer agent is a compound capable ofintroducing a group such as the above-listed alkyl groups, aralkylgroups and aryl groups into the end of a water-soluble polymer (C). Sucha compound is preferred to contain at least one type of a hydrophobicgroup selected from the group consisting of alkyl groups, aralykylgroups and aryl groups each having 3 to 100 carbon atoms, preferably 5to 50, especially preferably 7 to 30 carbon atoms. Examples of preferredchain transfer agents are thiols, disulfides, thioethers and the likehaving a hydrophobic group such as alkylthio groups, aralkylthio groupsand arylthio groups each having 7 to 20 carbon atoms.

The main-chain structure of a water-soluble polymer (C) includes amonomer unit having a nitrogen-containing functional group, especially aunit derived from a vinyl monomer having a nitrogen-containingfunctional group. It may also include other monomer units such as vinylmonomers that do not have a nitrogen-containing functional group. As fora vinyl monomer having a nitrogen-containing functional group,acrylamides and their derivatives and heterocyclic monomers having anitrogen-containing functional group are preferred. Especially, thosehaving an amide group are preferred.

Specific examples of vinyl monomers having a nitrogen-containingfunctional group are vinyl monomers having an amide group such asacrylamide, N,N-dimethylacrylamide, N-isopropylacrylamide,N,N-diethylacrylamide, N,N-dimethylaminopropylacrylamide,t-butylacrylamide, diacetonacrylamide, N,N′-methylenebis acrylamide,N-vinyl-N-methylacrylamide, n-vinyl-2-pyrrolidone, andN-vinylcaprolactam. Among those, acrylamides, N-vinylpyrrolidone, andN-vinylcaprolactam are especially preferred.

When the main-chain site of a water-soluble polymer (C) contains a vinylmonomer unit having a nitrogen-containing functional group, the numberof repeated carbon atoms, namely, its degree of polymerization, ispreferred to be 2 to 1000.

Namely, in the second embodiment of the present invention, awater-soluble polymer (C) is preferred to be a polymer compound havingat least one terminal hydrophobic group selected from the groupconsisting of alkylthio groups, aralkylthio groups and arylthio groupsas well as having at least one nitrogen-containing functional groupselected from the group consisting of a pyrrolidone skeleton,caprolactam skeleton, and amide skeleton.

In another aspect of the second embodiment of the present invention, awater-soluble polymer (C) is preferred to be a polymer compound obtainedby polymerizing at least one chain transfer agent selected from thegroup consisting of n-dodecyl mercaptan and n-octyl mercaptan and atleast one vinyl monomer selected from the group consisting ofN-vinylpyrrolidone, N-vinylcaprolactam, and acrylamides.

(Method for Producing Water-Soluble Polymer (C))

A water-soluble polymer (C) is produced, for example, by the followingmethod: a main-chain structure is produced by polymerizing the vinylmonomer above having a nitrogen-containing functional group preferablyin the presence of a polymerization initiator under conditions of 80° C.and normal pressure, and the above-described chain transfer agent isthen added for subsequent reactions. Alternatively, a water-solublepolymer (C) may also be produced by polymerizing the above vinyl polymerhaving a nitrogen-containing functional group in the presence of both apolymerization initiator and a chain transfer agent. Afterpolymerization, aging and cooling treatments are preferred to beconducted.

As long as the effects of the present invention are achieved, thepolymerization initiator is not limited to any specific type and it maybe, for example, radical polymerization initiators such as2,2′-azobis(2-methylbutyronitrile), 2,2′-azobis isobutyronitrile,2,2′-azobis (2,4-dimethylvaleronitrile) and 1,1-azobis(cyclohexanecarbonitrile).

As long as the effects of the present invention are achieved, the chaintransfer agent is not limited to any specific type and it may be, forexample, a mercaptan based chain transfer agent such as n-octylmercaptan and n-dodecyl mercaptan.

More specifically, the method for producing a water-soluble polymer (C)is preferred to include a step for dropping into a solvent a mixture ofthe above vinyl monomer having a nitrogen-containing functional group, achain transfer agent, and a polymerization initiator, which weredescribed above, and a solvent.

The weight ratio of mixing a vinyl monomer having a nitrogen-containingfunctional group and a chain transfer agent is preferred to be 100:0.01to 100:10, more preferably 100:0.1 to 100:5.

In addition, the temperature for dropping polymerization is preferred tobe 60 to 95° C., more preferably 70 to 85° C.

Also, after the completion of dropping polymerization, it is preferredto further conduct an aging step at 70 to 95° C. for 2 to 8 hours.

The weight average molecular weight of a water-soluble polymer (C) ispreferred to be 500 to 5000. Excellent surface activity is likely to beexhibited by setting the weight average molecular weight of awater-soluble polymer (C) in such a range. Such a weight averagemolecular weight is the value measured by using GPC (gel permeationchromatography) in water solvent and in terms of polyethylene glycol.The weight average molecular weight is more preferred to be 500 to 3000,and is especially preferred to be 500 to 1500 from the viewpoint ofcoating performance of the conductive composition in the secondembodiment of the present invention.

In addition, after the completion of polymerization, the solvent in thesurfactant (B) containing a water-soluble polymer (C) is preferred to beremoved by further conducting vacuum concentration or the like. Thesurfactant (B) containing a water-soluble polymer (C) may contain acompound (D1) having a Log Pow of 4 or more generated by reactions of apolymerization initiator and a chain transfer agent as described above.

In a method for producing a surfactant (B) of the present embodiment, asurfactant (B) containing a water-soluble polymer (C) is preferred tomake contact with an adsorbent so that a compound (D1) with anoctanol/water partition coefficient (Log Pow) of 4 or more is adsorbedand removed. An adsorbent is not limited specifically as long as theeffects of the present invention are achieved; for example, hydrophobicsubstances such as octadecyl-modified silica and activated carbon areused. Especially, activated carbon is preferred, since a compound (D1)with an octanol/water partition coefficient (Log Pow) of 4 or more inthe surfactant (B) is selectively removed.

For adsorbing and removing the compound, a surfactant (B) containing awater-soluble polymer (C) is preferred to be dissolved in a solvent andthen to make contact with an adsorbent.

The solvent is not limited specifically as long as the effects of thepresent invention are achieved; for example, water, organic solvents orthe like may be used. Especially, a mixed solvent of water and anorganic solvent is preferred, since the rate of removing a hydrophobiccompound, namely, a compound (D1), improves.

The ratio of mixing water and an organic solvent is preferred to be60/40 to 90/10. Examples of an organic solvent are alcohol solvents suchas isopropyl alcohol. In addition, the duration in which a surfactant(B) and an adsorbent are in contact is preferred to be 1 second or more.

Another method for producing a surfactant (B) of the present embodimentis as follows: a mixture containing a water-soluble polymer (C) and acompound (D1) with an octanol/water partition coefficient (Log Pow) of 4or more is prepared by using a vinyl monomer having anitrogen-containing functional group, a chain transfer agent forintroducing a terminal hydrophobic group and a polymerization initiator;and the mixture makes contact with the aforementioned adsorbent toadsorb and remove the compound (D1) with an octanol/water partitioncoefficient (Log Pow) of 4 or more.

In a conductive composition according to the second embodiment of thepresent invention, the content of a compound (D1) with an octanol/waterpartition coefficient (Log Pow) of 4 or more is 0.001 mass % or less,relative to the total mass of the conductive composition. In addition,since the content of a compound (D1) in the surfactant (B) is 1 part bymass or less based on 100 parts by mass of the surfactant (B), namely, 1mass % or less, relative to the total mass of the surfactant (B),clogging of the filter is reduced when filtrating the conductivecomposition of the second embodiment. Accordingly, the surfactant (B) issuitable as an additive for a conductive composition from whichcontaminants need to be removed by filtration.

(Method for Producing Conductive Composition of the Second Embodiment)

A conductive composition according to the second embodiment of thepresent invention is produced by mixing a surfactant (B) and aconductive polymer (A) described above. A conductive composition of thesecond embodiment is preferred to be a solution that further containswater as a solvent. In addition to water, the conductive compositionsolution may contain another solvent such as an organic solvent.

In addition, the content of a surfactant (B) in the conductivecomposition of the second embodiment is preferred to be 0.01 to 20 mass%, more preferably 0.01 to 15 mass %, relative to the total mass of theconductive composition. Also, the content of a conductive polymer (A) inthe conductive composition of the second embodiment is preferred to be0.01 to 50 mass %, more preferably 0.01 to 2 mass %, relative to thetotal mass of the conductive composition. Furthermore, a conductivecoating film is formed by applying the conductive composition of thesecond embodiment on a substrate after the composition is filtratedthrough a filter.

(Conductive Polymer (A) in the Second Embodiment of the PresentInvention)

As a conductive polymer (A) in the conductive composition of the secondembodiment of the present invention, the conductive polymer (A)described in the first embodiment above can be used. Preferred examplesare also the same.

(Polymer Compound (Y))

In addition, regarding a conductive composition of the secondembodiment, the strength and roughness of a conductive coating film areenhanced or adjusted by mixing a polymer compound (Y) in the conductivecomposition. More specifically, polyvinyl alcohol derivatives such aspolyvinyl formal and polyvinyl butyral; polyacrylamides such aspolyacrylamide, poly(N-t-butyl acrylamide) andpolyacrylamidemethylpropane sulfonic acid; polyvinyl pyrrolidones,polyacrylic acids, water-soluble alkyd resins, water-soluble melamineresins, water-soluble urea resins, water-soluble phenolic resins,water-soluble epoxy resins, water-soluble polybutadiene resins,water-soluble acrylic resins, water-soluble urethane resins,water-soluble acrylic styrene copolymer resins, water-soluble vinylacetate-acrylic copolymer resins, water-soluble polyester resins,water-soluble styrene-maleic acid copolymer resins, water-solublefluorocarbon resins, and their copolymers. When a polymer compound (Y)is included, its content is preferred to be 0.01 to 20 mass %, morepreferably 0.01 to 15 mass %, relative to the total mass of theconductive composition.

Moreover, the conductive composition of the second embodiment mayfurther contain various additives such as pigments, defoamers, UVabsorbers, antioxidants, heat resistance enhancers, leveling agents,anti-sag agents, matting agents, preservatives and the like, as needed.

A method for forming a conductive coating film using the conductivecomposition of the second embodiment is preferred to be conducted byapplying the conductive composition of the second embodiment on asubstrate after the composition is filtrated through a filter. Theconductive composition of the second embodiment is easily filtratedthrough a filter when the filter made of hydrophobic materials such aspolyethylene. In addition, it is preferred to apply the conductivecomposition of the second embodiment on at least one surface of asubstrate. The application method is not limited specifically as long asthe effects of the present invention are achieved; for example, spincoating, spray coating, dip coating, roll coating, gravure coating,reverse coating, roll brushing, air knife coating, curtain coatingmethods and the like.

Also, examples of the substrate are the same as those described in thefirst embodiment above. Examples of the steps for applying theconductive composition on a substrate are the same as the stepsdescribed in the first embodiment above.

To form a conductive coating film, the conductive composition of thesecond embodiment is applied on a substrate after the composition isfiltrated through a filter, and then the substrate is kept at roomtemperature or heat is applied on the substrate. The heating temperatureis preferred to be in a range of 40° C. to 250° C. to obtain aconductive coating film with excellent conductivity.

Another aspect of the conductive composition according to the secondembodiment of the present invention is as follows: a conductivecomposition containing a conductive polymer (A), a surfactant (B) andwater; the surfactant (B) is a water-soluble polymer (C) having anitrogen-containing functional group and a terminal hydrophobic group,the water-soluble polymer (C) is a polymer compound obtained bypolymerizing a mercaptan-based chain transfer agent and a vinyl monomerhaving an amide group, the content of a compound (D1) with anoctanol/water partition coefficient (Log Pow) of 4 or more in theconductive composition is 0.001 mass % or less, relative to the totalmass of the conductive composition; the content of a conductive polymer(A) is 0.01 to 50 mass %, the content of the surfactant (B) is 0.01 to20 mass % and the content of water is 50 to 99.5 mass % based on thetotal mass of the conductive composition, and the total content of eachcomponent does not exceed 100 mass %.

In addition, another aspect of the conductive composition according to asecond embodiment of the present invention is as follows: a conductivecomposition containing a conductive polymer (A), a surfactant (B) andwater, the surfactant (B) is a water-soluble polymer (C) having anitrogen-containing functional group and a terminal hydrophobic group,the water-soluble polymer (C) is a polymer compound obtained bypolymerizing a mercaptan-based chain transfer agent and a vinyl monomerhaving an amide group, the content of a compound (D1) with anoctanol/water partition coefficient (Log Pow) of 4 or more in theconductive composition is 0.001 mass % or less, relative to the totalmass of the conductive composition, the compound (D1) is a reactantobtained by a polymerization initiator and a chain transfer agent usedfor producing the water-soluble polymer (C), the content of a conductivepolymer (A) is 0.01 to 50 mass %, the content of the surfactant (B) is0.01 to 20 mass % and the content of water is 50 to 99.5 mass %, basedon the total mass of the conductive composition, and the total contentof each component does not exceed 100 mass %.

Third Embodiment Conductive Composition

A conductive composition according to the third embodiment of thepresent invention is characterized in that a water-soluble polymer (C)in a surfactant (B) contained in the conductive composition according tothe second embodiment described above is a water-soluble polymer (C1)having a nitrogen-containing functional group and a terminal hydrophobicgroup and with the weight average molecular weight of 2000 or more.

In addition, a conductive polymer (A) is preferred to have a monomerunit represented by the following general formula (1).

(In formula (1), R¹ to R⁴ each independently represents a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup or salt thereof.)

Also, the conductive polymer (A) is preferred to be a conductive polymerthat has at least one acidic group selected from the group consisting ofsulfonic acid groups and carboxyl groups.

The third embodiment of the present invention has the following aspects:

[1] a conductive composition containing a conductive polymer (A) whichhas at least one acidic group selected from the group consisting ofsulfonic acid groups and carboxyl groups and a water-soluble polymer(C1) which has a nitrogen-containing functional group and a hydrophobicgroup and with the weight average molecular weight of 2000 or more;[2] the conductive composition described in [1], wherein thenitrogen-containing functional group is an amide group;[3] the conductive composition described in [1] or [2], wherein theterminal hydrophobic group contains at least one hydrophobic groupselected from the group consisting of alkyl chains having 5 to 100carbon atoms, aralkyl chains having 5 to 100 carbon atoms and arylchains having 5 to 100 carbon atoms;[4] the conductive composition described in [1] or [2], wherein theterminal hydrophobic group contains at least one hydrophobic groupselected from the group consisting of alkylthio groups having 5 to 100carbon atoms, aralkylthio groups having 5 to 100 carbon atoms andarylthio groups having 5 to 100 carbon atoms;[5] The conductive composition described in any one of [1] to [4],wherein the conductive polymer (A) contains a monomer unit representedby the following general formula (1);

(In formula (1), R¹ to R⁴ each independently represents a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom (—F, —Cl, —Br, or I). In addition, at least one of R¹ to R⁴is an acidic group or salt thereof. Also, an acidic group represents asulfonic acid group or a carboxyl group.)

[6] a conductor including a substrate and a coating film formed byapplying the conductive composition described in any one of [1] to [5]on at least one surface of the substrate; and[7] A laminate including a substrate, a resist layer formed on at leastone surface of the substrate, and a coating film formed by applying theconductive composition described in any one of [1] to [5] on the resistlayer.

(Conductive Polymer (A) in the Third Embodiment of the PresentInvention)

As a conductive polymer (A) in the conductive composition according tothe third embodiment of the present invention, the conductive polymer(A) described in the first embodiment above is used. Preferred examplesare also the same.

(Water-Soluble Polymer (C1))

In a conductive composition according to the third embodiment of thepresent invention, a water-soluble polymer (C1) indicates awater-soluble polymer having a nitrogen-containing functional group anda hydrophobic group and with a weight average molecular weight of 2000or more.

In the conductive composition of the third embodiment, a water-solublepolymer (C1) works as a surfactant.

When a water-soluble polymer (C1) having a weight average molecularweight at a certain weight or more is used as a surfactant (B) to becombined with the conductive polymer (A), a conductive coating film isformed to exhibit excellent coating performance with smaller surfaceroughness, where a laminate such as resist coated on the substrate isless likely to be affected negatively.

Namely, the conductive composition according to the third embodiment ischaracterized by containing the conductive polymer (A) described in thefirst and second embodiments above and the water-soluble polymer (C1).

In addition, the nitrogen-containing functional group of thewater-soluble polymer (C1) is preferred to be an amide group from theviewpoint of dissolubility.

A terminal hydrophobic group is not limited specifically as long as itcontains an alkyl chain, aralkyl chain or aryl chain and the effects ofthe present invention are achieved.

Examples of a terminal hydrophobic group are, for example, alkyl groups,aralkyl groups, aryl groups, alkoxyl groups, aralkyloxy groups, aryloxygroups, alkylthio groups, aralkylthio groups, arylthio groups, primaryor secondary alkylamino, aralkylamino and arylamino groups.

Here, a terminal hydrophobic group indicates a hydrophobic groupintroduced to a “water-soluble polymer end” as described in the secondembodiment above.

In the conductive composition according to the third embodiment of thepresent invention, the terminal hydrophobic group in a water-solublepolymer (C1) is preferred to have at least one group selected from thegroup consisting of alkyl chains having 5 to 100 carbon atoms, aralkylchains having 7 to 100 carbon atoms and aryl chains having 6 to 100carbon atoms from the viewpoints of dissolubility and surface activity.

Furthermore, the terminal hydrophobic group is more preferred to have atleast one group selected from the group consisting of alkyl chainshaving 6 to 70 carbon atoms, aralkyl chains having 7 to 70 carbon atomsand aryl chains having 6 to 70 carbon atoms, and is especially preferredto have at least one group selected from the group consisting of alkylchains having 7 to 30 carbon atoms, aralkyl chains having 7 to 30 carbonatoms and aryl chains having 7 to 30 carbon atoms.

In addition, from the viewpoint of surface activity, the terminalhydrophobic group is preferred to be at least a group selected from thegroup consisting of alkylthio groups having 5 to 100 carbon atoms,aralkylthio groups having 7 to 100 carbon atoms and arylthio groupshaving 6 to 100 carbon atoms.

Moreover, the terminal hydrophobic group is further preferred to be atleast one group selected from the group consisting of alkylthio groupshaving 7 to 50 carbon atoms, aralkylthio groups having 6 to 50 carbonatoms and arylthio groups having 6 to 50 carbon atoms, and is especiallypreferred to be at least one group selected from the group consisting ofalkylthio groups having 7 to 30 carbon atoms, aralkylthio groups having7 to 30 carbon atoms and arylthio groups having 7 to 30 carbon atoms.

More specific examples are dodecyl groups, octyl groups and the like.

Here, the terminal hydrophobic group is preferred to have at least onegroup selected from the group consisting of the above alkyl chains,aralykyl chains and aryl chains. From the viewpoints of dissolubilityand surface activity, it is further preferred to be an alkylthio grouphaving an alkyl chain and a sulfur atom, an aralkylthio group having anaralkyl chain and a sulfur atom, or an arylthio group having an arylchain and a sulfur atom.

Among those, from the viewpoints of dissolubility and surface activity,alkylthio groups are especially preferred.

The water-soluble polymer (C1) of the third embodiment has anitrogen-containing functional group and a terminal hydrophobic group,and with weight average molecular weight is 2000 or more. The weightaverage molecular weight of the water-soluble polymer (C1) is preferredto be 2000 to 1,000,000, more preferably 2500 to 100,000, especiallypreferably 5000 to 10,000.

As long as the effects of the present invention are achieved, themain-chain structure of a water-soluble polymer (C1) is not limitedspecifically if it is a homopolymer of a vinyl monomer having anitrogen-containing functional group or a copolymer of another vinylmonomer and if it is water soluble.

Here, the main-chain structure of a water-soluble polymer (C1) indicatesa monomer unit having a nitrogen-containing functional group, excludingmonomer units derived from the terminal hydrophobic group of thewater-soluble polymer (C1), as described in the second embodiment above.

The nitrogen-containing functional group is preferred to be an amidegroup, and examples of a vinyl monomer having an amide group areacrylamides and their derivatives, N-vinyl lactam and the like. Specificexamples are the same as those listed for the nitrogen-containing groupin the second embodiment above, and preferred examples are also thesame.

(Method for Producing Water-Soluble Polymer (C1))

For producing a water-soluble polymer (C1), it is not limited to anyspecific method for introducing a hydrophobic group to an end of awater-soluble polymer having a nitrogen-containing functional group aslong as the effects of the present invention are achieved. Anintroduction method by selecting a chain transfer agent used for vinylpolymerization is easy and preferable.

In the above method, a chain transfer agent is not limited specificallyas long it is capable of introducing the above terminal hydrophobicgroup and the effects of the present invention are achieved. Thiol,disulfide, thioether and the like are preferred to be used sincepreferred terminal hydrophobic groups such as alkylthio groups,aralkylthio groups and arylthio groups are easy to obtain. Inparticular, mercaptan-based chain transfer agents, styrene-based chaintransfer agents and the like are listed, and n-dodecyl mercaptan andn-octyl mercaptan are preferred.

More specifically, a production method is preferred to include the stepfor obtaining a water-soluble polymer (C); that is, a mixture of theabove vinyl monomer having the nitrogen-containing functional group, achain transfer agent, a polymerization initiator and a solvent, isdropped into a solvent to carry out polymerization.

The weight ratio of mixing the vinyl monomer having thenitrogen-containing functional group and a chain transfer agent ispreferred to be 100:0.01 to 100:10, more preferably 100:0.1 to 100:5.

In addition, the temperature for performing the dropping polymerizationis preferred to be 60 to 95° C., more preferably 70 to 85° C.

Furthermore, the production method is preferred to include an aging stepat 70 to 95° C. for 2 to 8 hours, after the dropping polymerization.

The number of repeated monomer units in the main-chain structure havinga nitrogen-containing functional group in a water-soluble polymer (C1),namely, the degree of polymerization of the vinyl monomer having anitrogen-containing functional group is preferred to be 10 to 100,000,more preferably 15 to 1,000 and especially preferably 20 to 200, fromthe viewpoint of dissolubility of the water-soluble polymer (C1).

In addition, from the viewpoint of surface activity, the ratio betweenthe molecular weight of the main-chain structure having anitrogen-containing functional group (hereinafter, may also be referredto as “molecular weight of the water-soluble part”) and the molecularweight of the terminal hydrophobic site (hereinafter, may also bereferred to as “molecular weight of the hydrophobic part”), namely, theratio of (molecular weight of the water-soluble part)/(molecular weightof the hydrophobic part) in the water-soluble polymer (C) is preferredto be 1 to 150, more preferably 5 to 100. Here, the “molecular weight ofthe water-soluble part” and the “molecular weight of the hydrophobicpart” can calculate from the ratio of the weight average molecularweight of the obtained water-soluble polymer (C1) and the respectivelyadded amounts of the monomer which constitutes the main-chain structureand the chain transfer agent which constitutes the terminal hydrophobicsite.

Unlike conventional surfactants, the water-soluble polymer (C1) iscapable of expressing surface activity by the main-chain structure(water-soluble part) having a nitrogen-containing functional group andby a terminal hydrophobic group (hydrophobic part).

Therefore, since the conductive composition does not contain acid orbase and byproduct generated by hydrolysis, the conductive compositioncontaining a water-soluble polymer (C1) according to the thirdembodiment enhances coating performance without negatively affecting asubstrate or a laminate such as a resist coated on a substrate.

Moreover, by setting the weight average molecular weight of thewater-soluble polymer (C1) at 2000 or more, it is able to reduce thecontent of components having low molecular weight.

Thus, when the conductive composition of the third embodiment is appliedto form a conductor on a resist layer, it is able to suppress that theresist surface be dissolved by migrating the component having lowmolecular weight to the interface of the resist layer

Accordingly, even if the conductor obtained by applying the conductivecomposition of the third embodiment that contains the water-solublepolymer (C1) to the resist surface was used under a high temperature of100° C. or more, the film thickness of the resist is less likely todecrease. Also, surface roughness of the conductor caused by thecomponent having low molecular weight is suppressed.

The glass transition temperature of the water-soluble polymer (C1) ispreferred to be 60° C. to 250° C., more preferably 65° C. to 200° C.,especially preferably 70° C. to 150° C., from the viewpoint of fluidity.

Here, “the component having low molecular weight” indicates oligomercomponents with a weight average molecular weight of 500 to 1300.

Moreover, in conventional surfactants such as a water-soluble polymerdescribed in Patent Literature 1 (hereinafter, may also be referred toas “water-soluble polymer (Z)”), there are problems that effects tosuppress the surface roughness of a conductive coating film derived fromthe skeleton of a conductive polymer are insufficient.

However, the water-soluble polymer (C1) of the present invention iscapable of reducing roughness on the surface of a conductive coatingfilm derived from the skeleton of a conductive polymer (A) by improvingthe weight average molecular weight of a water-soluble polymer.

Accordingly, the conductive composition of the third embodiment thatcontains the water-soluble polymer (C1) as a surfactant is capable offorming a conductive coating film with surface roughness applicable to anext-generation process for semiconductor devices.

(Method for Producing Conductive Composition of the Third Embodiment)

The conductive composition according to the third embodiment of thepresent invention is produced by mixing the water-soluble polymer (C1)with the conductive polymer (A) as described in the first embodimentabove.

The water-soluble polymer (C1) is preferred to be used by beingdispersed in a later-described solvent (X), and its content is preferredto be 0.01 to 20 parts by mass, more preferably 0.01 to 15 parts by massbased on 100 parts by mass of solvent (X).

In the conductive composition of the third embodiment, the content ofthe water-soluble polymer (C1) is preferred to be 0.01 to 20 mass %,more preferably 0.01 to 15 mass %, relative to the total content (100mass %) of the conductive composition. In addition, in the conductivecomposition of the third embodiment, the content of the conductivepolymer (A) is preferred to be 0.01 to 50 mass %, more preferably 0.01to 2 mass %, relative to the total mass of the conductive composition.

Moreover, the ratio of the water-soluble polymer (C1) and conductivepolymer (A) is preferred to be 1:9 to 9:1, more preferably 2:8 to 8:2.

(Solvent (X))

A solvent (X) used in the third embodiment of the present invention isnot limited specifically as long as it can dissolve the conductivepolymer (A) and the water-soluble polymer (C1) and the effects of thepresent invention are achieved. Water or a mixture of water and thefollowing is preferred: alcohols such as methanol, ethanol, isopropylalcohol, propyl alcohol and butanol; ketones such as acetone andethylisobutylketone; ethylene glycols such as ethylene glycol andethylene glycol methylether; propylene glycols such as propylene glycol,propylene glycol methyl ether, propylene glycol ethyl ether, propyleneglycol butyl ether and propylene glycol propyl ether; amides such asdimethylformamide and dimethylacetamide; and pyrrolidons such asN-methylpyrrolidone and N-methylpyrrolidone.

When a mixture with water is used as a solvent (X), the ratio of waterto organic solvent is preferred to be 1/100 to 100/1, more preferably2/100 to 100/2.

Also, in the conductive composition of the third embodiment, a preferredamount of a solvent (X) to be used is 2 to 10,000 parts by mass, morepreferably 50 to 10,000 parts by mass, based on 1 part by mass, relativeto the conductive polymer (A).

The conductive composition of the third embodiment may contain thepolymer compound (Y) above to enhance the strength and surface roughnessof a conductive coating film, and the preferred amount of compound (Y)is the same as in the second embodiment above.

Moreover, the conductive composition of the third embodiment may furthercontain various additives such as pigments, defoamers, UV absorbers,antioxidants, heat resistance enhancers, leveling agents, anti-sagagents, matting agents, preservatives and the like, as needed.

(Conductor and Laminate)

A conductor obtained by the conductive composition according to thethird embodiment of the present invention has a substrate and aconductive coating film formed by applying the conductive composition onat least one surface of the substrate.

Also, a laminate obtained by using the conductive composition of thethird embodiment has a substrate, a resist layer formed on at least onesurface of the substrate and a coating film formed by applying theconductive composition on the resist layer.

A method for applying the conductive composition on a substrate is notlimited specifically as long as the effects of the present invention areachieved; for example, spin coating, spray coating, dip coating, rollcoating, gravure coating, reverse coating, roll brushing, air knifecoating, curtain coating methods and the like may be used.

A substrate is not limited specifically as long as the effects of thepresent invention are achieved; for example,

polyester resins such as PET and PBT, polyolefin resins represented bypolyethylene and polypropylene, vinyl chloride, nylon, polystyrene,polycarbonate, epoxy resin, fluororesin, polysulfone, polyimide,polyurethane, phenolic resin, silicone resin, finished products ofvarious polymer compounds such as synthetic paper, film, paper, iron,glass, fused quartz, various wafers, aluminum, copper, zinc, nickel andstainless steel; and products on which various coating materials,photosensitive resin, resist or the like are coated on the materialslisted above.

A step for applying a conductive composition to the substrate above maybe employed before or during the process for manufacturing thesubstrate, for example, uniaxial stretching, biaxial stretching, moldingor embossing. Alternatively, a step for applying the composition to thesubstrate may be employed after those processing steps are completed.

Also, since the conductive composition of the third embodiment hasexcellent coating properties, a conductive coating film may be formed byapplying a conductive composition on top of the substrate surface whereone of various coating materials or photosensitive materials is alreadycoated.

A conductor formed by the conductive composition of the third embodimentis produced when a conductive coating film is formed on at least onesurface of a substrate by coating and drying the conductive composition,and then the film is kept at normal temperature (25° C.) for 1 to 60minutes or heat is applied to the film.

When heat is applied, the temperature is preferred to be in a range of40° C. to 250° C., more preferably in a range of 60° C. to 200° C., fromthe viewpoint of conductivity.

The treatment time is preferred to be one hour or less, more preferably30 minutes or less, from the viewpoint of stability.

In addition, another aspect of the conductive composition according tothe third embodiment of the present invention is as follows: theconductive composition contains a conductive polymer (A), a surfactant(B) and water, the surfactant (B) is a water-soluble polymer (C1) whichhas a nitrogen-containing functional group and a terminal hydrophobicgroup and has a weight average molecular weight of 2000 or more, thecontent of the conductive polymer (A) is 0.01 to 50 mass %, the contentof the surfactant (B) is 0.01 to 20 mass % and the content of water is50 to 99.5 mass % based on the total mass of the conductive composition,and the total content of each component does not exceed 100 mass %.

Fourth Embodiment Conductive Composition

A conductive composition according to the fourth embodiment of thepresent invention contains a conductive polymer (A1) and a basiccompound (E1), and is characterized in that the basic compound (E1) hasa conjugated structure and two or more tertiary amines in the molecule.

In addition, the conductive composition is preferred to contain asurfactant (B).

Moreover, the surfactant (B) includes a water-soluble polymer (C) havinga nitrogen-containing functional group and a terminal hydrophobic group.In the conductive composition, the content of a compound (D1) with anoctanol/water partition coefficient (Log Pow) of 4 or more in theconductive composition is preferred to be 0.001 mass % or less, relativeto the total mass of the conductive composition.

Also, the conductive polymer (A1) is preferred to have a monomer unitrepresented by the following general formula (1).

(In formula (1), R¹ to R⁴ each independently represents a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R1 to R4 is an acidic groupor salt thereof.)

Also, the above conductive polymer (A) is preferred to be a conductivepolymer that has at least one acidic group selected from the groupconsisting of sulfonic acid groups and carboxyl groups.

Furthermore, the conductive polymer (A1) in the conductive compositionof the fourth embodiment is preferred to have a monomer unit representedby general formula (1) below.

(In formula (1), R¹ to R⁴ each independently represents a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup or salt thereof. Also, an acidic group represents a sulfonic acidgroup or a carboxyl group.)

(Conductive Polymer (A1) in the Fourth Embodiment of the PresentInvention)

A conductive polymer (A1) in the conductive composition according to thefourth embodiment of the present invention is obtained by removing abasic substance from the conductive polymer (A) described above in thefirst embodiment.

As described above, when a conductive composition containing aconventional conductive polymer is used to form a conductive coatingfilm on a resist layer, basic substances in the conductive coating filmmigrate to the resist layer, causing deactivation of acid in the exposedportion when the resist is a positive type, and thus deformation of theresist pattern or sensitivity change to a lower sensitivity range tendsto occur.

On the other hand, when the resist is a negative type, narrowedpatterns, reduction in film thickness, sensitivity change to a highersensitivity range or the like tend to occur.

However, by removing the basic substances from a reaction mixture,namely, a mixture of byproducts such as residual monomers in theconductive polymer, oligomers generated in side reactions, acidicsubstances (sulfate ions or the like, which are decomposed products ofmonomers and oxidizing agent), basic substances (ammonium ions or thelike, which are decomposed products of basic reaction auxiliary andoxidizing agent) and the like, migration of byproducts such as acidicsubstances and basic substances to the resist layer is suppressed, andadverse impact on the resist is suppressed when a conductive coatingfilm is formed on the resist layer using the conductive composition ofthe fourth embodiment, especially by a pattern forming method using achemically amplified resist and charged particle beams.

(Method for Producing Conductive Polymer (A1))

A conductive polymer (A1) is produced by a production method thatincludes a step for removing byproducts from the conductive polymer (A)above.

The method for removing byproducts is not limited specifically as longas the effects of the present invention are achieved. For example,various methods are available such as a column-type or batch-typeprocess using ion exchange resins, a process using ion-exchangemembranes, electrodialysis, and acid cleaning using a protonic acidsolution, heating, and precipitation through neutralization.

Among those, an ion-exchange method is especially effective. Using anion-exchange method, it is easier to effectively remove basic substancesexisting as reaction products of a salt and the acidic group of aconductive polymer (A1), residual monomers, and low-molecular weightacidic substances such as sulfate. Accordingly, a highly pure conductivepolymer (A1) solution is obtained.

Examples of ion-exchange methods are those using cation exchange resinor anion exchange resin, electrodialysis and the like.

When a basic reaction auxiliary or the like is removed by anion-exchange method, after a reaction mixture solution is formed bydissolving the reaction mixture in an aqueous medium to a desired solidcontent, namely, a solid content of 0.01 to 10 mass %, the basicreaction auxiliary and byproducts are removed.

Examples of an aqueous medium are water, water-soluble organic solventand a mixed solvent of water and water-soluble organic solvent.

Water-soluble organic solvents are organic solvents that dissolve inwater. For example, alcohols such as methanol, ethanol, 2-propanol,1-propanol and 1-butanol; ketones such as acetone, methylethylketone,ethylisobutylketone and methylisobutylketone; ethylene glycols such asethylene glycol, ethylene glycol methylether and ethyleneglycol-mono-n-propylether; propylene glycols such as propylene glycol,propylene glycol methyl ether, propylene glycol ethyl ether, propyleneglycol butyl ether and polypropylene glycol propyl ether; amides such asdimethylformamide and dimethylacetamide; pyrrolidons such asN-methylpyrrolidone and N-methylpyrrolidone; methyl lactate, ethyllactate, β-methoxyisobutyric acid methyl ester, and hydroxyethyl esterssuch as α-hydroxyisobutyric acid methyl ester. Among those, alcohols andpyrrolidons are preferred from the viewpoint of dissolubility.

When an ion-exchange method using ion exchange resin is employed, thecontent of a sample solution, namely, the solution containing aconductive polymer (A) (hereinafter referred to as a “conductive polymer(A) solution”) to the ion exchange resin, is preferred to be 10 times byvolume, more preferably 5 times by volume, relative to the volume of theion exchange resin when it is a reaction mixture solution with a solidcontent of 5 mass %, that is, a conductive polymer (A) solution.

As for cation exchange resin, for example, “Amberlite IR-120B” made byOrgano Corporation may be used; and as for anion exchange resin,“Amberlite IRA 410” made by Organo Corporation, for example, is listed.

Namely, when byproducts are removed from the conductive polymer (A)using an ion-exchange method, it is preferred to include a step forcontacting a conductive polymer (A) solution with a column containingion exchange resin. In addition, when the conductive polymer (A)solution passes the column, the flow rate is preferred to be 10 to 1000mL/min, more preferably 20 to 500 mL/min. Also, the temperature when thesolution makes contact with ion exchange resin is preferred to be 15 to30° C.

When electrodialysis is used, the ion-exchange membrane forelectrodialysis is not limited specifically as long as the effects ofthe present invention are achieved. To suppress permeation of impuritiescaused by diffusion, it is preferred to use a permselective ion-exchangemembrane for monovalent ions, for example, an ion exchange membrane witha polystyrene structure, and a cutoff molecular weight of 300 or lessand 100 or more. As for such an ion-exchange membrane, for example“Neosepta CMK (cation exchange membrane, cutoff molecular weight of300)” and “Neosepta AMX (anion exchange membrane, cutoff molecularweight of 300)” made by Astom Corporation are preferred.

In addition, as an ion-exchange membrane used for electrodialysis,bipolar membrane, which is an ion-exchange membrane with a bondedstructure of an anion exchange layer and a cation exchange layer, mayalso be used. As for such bipolar membrane, for example “PB-1E/CMB” madeby Astom Corporation is suitable.

The current density in electrodialysis is preferred to be limitingcurrent density or less. The applied voltage at the bipolar membrane ispreferred to be 10 to 50 V, more preferably 25 to 35 V.

Namely, to remove byproducts from a conductive polymer (A) throughelectrodialysis, it is preferred to include a step for flowing theconductive polymer (A) solution through a permselective ion-exchangemembrane for monovalent ions.

(Basic Compound (E1))

The basic compound (E1) is not limited to any specific type as long asthe effects of the present invention are achieved and it is a basiccompound having a conjugated structure and two or more tertiary aminesin the molecule. From the viewpoint of diffusion of the base itself, acompound with a boiling point of 120° C. or more is preferred. Thenumber of tertiary amines in the molecule of a basic compound (E1) ispreferred to be 2 to 6, more preferably 2 to 3.

“Having two or more tertiary amines in the molecule” above indicates atleast one tertiary amine is included in a conjugated structure, namely,a cyclic structure. Here, examples of a conjugated structure, namely, ofa cyclic structure, are an aromatic ring structure having 6 to 10 carbonatoms and an alicyclic structure having 5 to 15 carbon atoms.

Specific examples of a basic compound (E1) are pyridine derivatives witha substituted tertiary amino group such as 4-dimethylaminopyridine,4-dimethylaminomethylpyridine and 3,4-bis(dimethylamino)pyridine;1,5-diazabicyclo[4.3.0]-5-nonene (DBN),1,8-diazabicyclo[5.4.0]-7-undecene (DBU), and their derivatives. Amongthose, from the viewpoint of water solubility, the basic compound (E1)is preferred to be 4-dimethylaminopyridine,4-dimethylaminomethylpyridine, 1,5-diazabicyclo[4.3.0]-5-nonene (DBN) or1,8-diazabicyclo[5.4.0]-7-undecene (DBU). Those basic compounds (E1) maybe used alone or in combination of two or more in any proportion.

When the basic compound (E1) is used, it is thought to work efficientlyon the acidic group of a conductive polymer (A1), and enhances thestability of the conductive polymer (A1). Here, to efficiently work onthe acidic group of a conductive polymer (A1) means stableneutralization is attained because of its high boiling point and strongbase properties. As a result, the acidic group of a conductive polymer(A1) in the conductive coating film is prevented from becoming unstable,and thus generation of acidic substances is reduced. Accordingly,migration of the acidic substances from the conductive coating film tothe resist layer is suppressed.

(Method for Producing Conductive Composition of the Fourth Embodiment)

The conductive composition according to the fourth embodiment of thepresent invention contains a conductive polymer (A1) and a basiccompound (E1).

A method for introducing a basic compound (E1) into a conductive polymer(A1) is not limited specifically as long as the effects of the presentinvention are achieved. A basic compound (E1) may be added to aconductive polymer (A1) solution at any selected temperature and rate.It is usually preferred to maintain a conductive polymer (A1) solutionat room temperature and to add a basic compound (E1) while the mixtureis being stirred.

In the present application, “room temperature” indicates 25° C.

The content of a basic compound (E1) in the conductive composition ofthe fourth embodiment is described in detail later, but usually, fromthe viewpoint of stability of the acidic group of a conductive polymer(A1) solution, its content is preferred to be 1 to 100 mol %, morepreferably 50 to 80 mol %, especially preferably 60 to 80 mol %, per 1mol % of the conductive polymer (A1) in the conductive composition (A1)solution.

If the content of a basic compound (E1) per 1 mol % of the conductivepolymer (A1) is 50 mol % or more or 60 mol % or more, migration ofacidic substances from the conductive coating film to the resist layercaused by heating is sufficiently suppressed when the conductive coatingfilm is formed on the resist using the conductive composition. On theother hand, if the content of the basic compound is 80 mol % or less,properties of a conductive coating film, namely, conductivity andcoating performance, are maintained.

In addition, the content of a basic compound (E1) in the conductivecomposition of the fourth embodiment is preferred to be 0.001 to 10 mass%, more preferably 0.01 to 5 mass %, relative to the total mass of theconductive composition. Also, the content of a conductive polymer (A1)in the conductive composition of the fourth embodiment is preferred tobe 0.01 to 30 mass %, more preferably 0.05 to 10 mass %, relative to thetotal mass of the conductive composition.

As described above, when a conductive coating film is formed on a resistlayer, if acidic substances such as sulfate derived from decomposedmonomers or oxidizing agents migrate from the conductive coating film tothe resist layer, narrowed patterns, reduction in film thickness, and achange in sensitivity toward a higher sensitivity range tend to occur ifthe resist is a positive type. On the other hand, if the resist is anegative type, deformation of patterns and a change in sensitivitytoward a lower sensitivity range tend to occur.

In addition, as described above, even if byproducts are removed, theacidic group eliminated from the conductive polymer (A) due to heatduring the process of forming conductive coating film tends to causeproblems such as migration to the resist layer.

By contrast, according to the fourth embodiment of the presentinvention, since the conductive composition contains the basic compound(E1), it works effectively to monomers or sulfates and tends to easilyform stable salts. In addition, the acidic group of a conductive polymer(A1) is stabilized, and elimination of the acidic group when heat isapplied is suppressed.

Accordingly, especially when patterns are formed using chemicallyamplified resist by irradiating charged particle beams, migration ofacidic substances from the conductive coating film to the resist layeris suppressed, thereby lowering adverse effects on the resist layer suchas reduction in film thickness.

A surfactant may further be contained in the conductive composition ofthe fourth embodiment of the present invention.

The surfactant is not limited specifically as long as the effects of thepresent invention are achieved and as long as the coating performance onthe resist layer, film-forming performance and film-forming capabilityare enhanced. Nonionic surfactants and water-soluble polymers areusually used, and a surfactant (water-soluble polymer (Z)) having anitrogen-containing functional group and a terminal hydrophobic groupdescribed in JP2002-226721A is preferably used.

The surfactant is more preferred to include the surfactant (B) above. Byincluding the surfactant (B) to the conductive composition of the fourthembodiment is preferred, since filtration results of the conductivecomposition are enhanced.

Namely, another aspect of the conductive composition according to thefourth embodiment of the present invention is as follows:

the conductive composition contains a conductive polymer (A1), a basiccompound (E1) and a surfactant (B), the surfactant (B) contains awater-soluble polymer (C) having a nitrogen-containing functional groupand a terminal hydrophobic group, and the content of a compound (D1)with an octanol/water partition coefficient (Log Pow) of 4 or more inthe conductive composition is preferred to be 0.001 mass % or less,relative to the total mass of the conductive composition.

In the surfactant (B) contained in the conductive composition of thefourth embodiment, the water-soluble polymer (C) may be thewater-soluble polymer (C1) described above in the third embodiment ofthe present invention.

Namely, another aspect of the conductive composition of the fourthembodiment is as follows: the conductive composition contains aconductive polymer (A), a basic compound (E1) and a surfactant (B), anda water-soluble polymer (C) in the surfactant (B) is preferred to be awater-soluble polymer (C1) having a nitrogen-containing functional groupand a terminal hydrophobic group, whose weight average molecular weightis 2000 or more.

Including a surfactant (B) containing the water-soluble polymer (C1) tothe conductive composition of the fourth embodiment is preferred, sincethe coating performance of the conductive composition is enhanced andsurface roughness of the conductor is suppressed. Moreover, includingsuch a surfactant (B) is also preferred because migration of componentshaving low molecular weight from the conductor to the resist surface issuppressed so as not to cause a reduction in the film thickness of theresist layer.

Also, in the fourth embodiment, if another surfactant—except for thesurfactant (B)—having a nitrogen-containing functional group and aterminal hydrophobic group is contained in the conductive composition,the number of monomer units at the main-chain part having anitrogen-containing functional group of the surfactant is preferred tobe 2 to 100,000, more preferably 2 to 1000, and especially preferably 2to 200. Here, if the number of monomer units having anitrogen-containing functional group in the water-soluble part is toogreat, the surface activity tends to decrease. Regarding the molecularweight of the main chain in the water-soluble part having anitrogen-containing functional group and the molecular weight of theterminal hydrophobic part (alkyl group, aralkyl group, aryl group site)in a surfactant, if the ratio (molecular weight of water-solublepart/molecular weight of hydrophobic part) is approximately 0.3 to 170,such a surfactant is especially preferred. Unlike conventionalsurfactants, such a surfactant having a nitrogen-containing functionalgroup and a terminal hydrophobic group exhibit surface activity by thehydrophilic main-chain part having a nitrogen-containing functionalgroup and by the terminal hydrophobic group. In addition, since such asurfactant does not contain acid or base and does not generatebyproducts caused by hydrolysis, no adverse effect is exerted on thesubstrate or the resist coated on the substrate, and coating performanceis enhanced without containing another surfactant.

The content of a surfactant contained in the conductive composition ofthe fourth embodiment is 0.01 to 20 parts by mass, preferably 0.01 to 15parts by mass based on 100 parts by mass of an aqueous medium. Here,“aqueous medium” indicates water, water-soluble organic solvents, ormixed solvents of water and water-soluble organic solvents.

Namely, in the fourth embodiment of the present invention, the contentof a surfactant (B) is preferred to be 0.01 to 50 mass %, morepreferably 0.1 to 20 mass %, relative to the total mass of theconductive composition. In addition, when a water-soluble polymer (C) inthe surfactant (B) is a water-soluble polymer (C1) above, the content ofthe surfactant (B) that includes a water-soluble polymer (C1) ispreferred to be 0.01 to 50 mass %, more preferably 0.1 to 20 mass %,relative to the total mass of the conductive composition of the fourthembodiment.

The conductive composition according to the fourth embodiment of thepresent invention is coated on a surface of a substrate or the resistlayer using a method generally employed for coating. Examples of amethod for coating the conductive composition of the fourth embodimentare those using coaters such as gravure coater, roll coater,curtain-flow coater, spin coater, bar coater, reverse coater, kisscoater, fountain coater, rod coater, air doctor coater, knife coater,blade coater, casting coater and screen coater; a spray method of spraycoating; and immersion methods such as dipping. Generally, a spin coateris used to apply a conductive composition on a resist coated on asilicon wafer or quartz mask substrate. For the purpose of improvingcoating properties, the conductive composition may include an alcohol, asurfactant or the like.

As described above, using the conductive composition of the fourthembodiment, a conductor is obtained where acidic substances are lesslikely to migrate to the resist layer when heat is applied on theconductor formed with the conductive composition.

In addition, when patterns are formed especially by a method usingchemically amplified resist and irradiating charged particle beams,acidic substances are suppressed from migrating from a conductor formedby the conductive composition of the fourth embodiment to the resistlayer. Thus, adverse impact on the resist layer such as a reduction infilm thickness or the like is lowered.

Moreover, the conductive composition of the fourth embodiment is usedfor conductors applied on the resist surface in a method for formingpatterns using chemically amplified resist and charged particle beams,and is also used for capacitors, transparent electrodes, semiconductorsand the like.

Among the above, when the conductive composition is used for formingconductive coating film in a pattern-forming method using chemicallyamplified resist and charged particle beams, the conductive compositionof the present invention is applied on the resist surface by a coatingmethod, and then patterns are formed by irradiating charged particlebeams. Accordingly, the adverse impact of the conductive coating film onthe resist layer is suppressed and desired resist patterns are formed.

Another aspect of the conductive composition of the fourth embodimentis: the conductive composition includes a conductive polymer (A1), abasic compound (E1) that has a conjugated structure and two or morenitrogen atoms in the molecule, and water; the basic compound (E1) is atleast one compound selected from the group consisting of4-dimethylaminopyridine, 4-dimethylaminomethylpyridine,3,4-bis(dimethylamino)pyridine, 1,5-diazabicyclo[4.3.0]-5-nonene (DBN),1,8-diazabicyclo[5.4.0]-7-undecene (DBU), and their derivatives; basedon the total mass of the conductive composition, the content of theconductive polymer (A1) is 0.01 to 30 mass %, the content of the basiccompound (E1) is 0.001 to 10 mass % and the content of water is 50 to99.5 mass %; and the total mass of each component does not exceed 100mass %.

Another aspect of the conductive composition of the fourth embodimentis: the conductive composition includes a conductive polymer (A), abasic compound (E1) that has a conjugated structure and two or morenitrogen atoms in the molecule, a surfactant (B) and water; the basiccompound (E1) is at least one compound selected from the groupconsisting of 4-dimethylaminopyridine, 4-dimethyl aminomethylpyridine,3,4-bis(dimethylamino)pyridine, 1,5-diazabicyclo[4.3.0]-5-nonene (DBN),1,8-diazabicyclo[5.4.0]-7-undecene (DBU), and their derivatives; thesurfactant (B) contains a water-soluble polymer (C) having anitrogen-containing functional group and a terminal hydrophobic group;the content of a compound (D1) with an octanol/water partitioncoefficient (Log Pow) of 4 or more in the conductive composition is0.001 mass % or less, relative to the total mass of the conductivecomposition; based on the total mass of the conductive composition, thecontent of the conductive polymer (A) is 0.01 to 30 mass %, the contentof the basic compound (E1) is 0.001 to 10 mass %, the content of thesurfactant (B) is 0.01 to 50 mass % and the content of water is 50 to99.5 mass %; and the total mass of each component does not exceed 100mass %.

Fifth Embodiment Conductive Composition

A conductive composition according to the fifth embodiment of thepresent invention contains a conductive polymer (A) and a basic compound(E2), wherein the basic compound (E2) is a quaternary ammonium salt inwhich at least one of its four groups bonded to a nitrogen atom is analkyl group having 3 or more carbon atoms.

In addition, the conductive composition is preferred to contain asurfactant (B).

Moreover, it is preferred that the surfactant (B) include awater-soluble polymer (C) having a nitrogen-containing functional groupand a terminal hydrophobic group, and the content of a compound (D1)with an octanol/water partition coefficient (Log Pow) of 4 or more inthe conductive composition is 0.001 mass % or less, relative to thetotal mass of the conductive composition.

Also, the conductive polymer (A) is preferred to have a monomer unitrepresented by the following general formula (1).

(In formula (1), R¹ to R⁴ each independently represents a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup or salt thereof.)

Also, the above conductive polymer (A) is preferred to have at least oneacidic group selected from the group consisting of sulfonic acid groupsand carboxyl groups.

Moreover, another aspect of the conductive composition of the fifthembodiment is that it contains a conductive polymer (A1) and a basiccompound (E2), and the basic compound (E2) is preferred to be aquaternary ammonium salt in which at least one of four groups bonded toa nitrogen atom is an alkyl group having 3 or more carbon atoms.

In addition, the fifth embodiment of the present invention has yetanother aspect as follows:

[1] A conductive composition including a conductive polymer (A) havingat least one acidic group selected from the group consisting of sulfonicacid groups and carboxyl groups, and a basic compound (E2) of aquaternary ammonium salt, wherein at least one of four groups bonded toa nitrogen atom in the basic compound (E2) is an alkyl group having 3 ormore carbon atoms.

[2] The conductive composition described in [1] further containing awater-soluble polymer (that excludes the conductive polymer (A) above).

[3] The conductive composition described in [1] or [2], wherein theconductive polymer (A) has a monomer unit represented by the followinggeneral formula (1).

In formula (1), R¹ to R⁴ each independently represents a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup. Here, an acidic group means a sulfonic acid group or a carboxylgroup.

[4] A conductive coating film formed by the conductive compositiondescribed in any one of [1] to [3].

(Conductive Polymer (A) in the Fifth Embodiment)

As a conductive polymer (A) in the conductive composition of the fifthembodiment of the present invention, the conductive polymer (A)described above in the first embodiment may be used. Its preferredexamples are the same.

(Basic Compound (E2))

A basic compound (E2) is a quaternary ammonium salt in which at leastone of four groups bonded to a nitrogen atom is an alkyl group having 3or more carbon atoms. From the viewpoint of improving the coatingproperties of the conductive composition of the fifth embodiment, atleast one of the four groups bonded to a nitrogen atom is preferred tobe an alkyl group having 4 or more carbon atoms. As long as the effectsof the present invention are achieved, the upper-limit number of thecarbon atoms in the substituent is not limited to a specific number.From the viewpoint of water solubility, 6 or less is preferred.

Examples of a basic compound (E2) are those represented by the followinggeneral formula (6).

In formula (6), R³⁴ to R³⁷ represents each independently selected fromthe group consisting of a hydrogen atom, a straight-chain orbranched-chain alkyl group having 1 to 16 carbon atoms and astraight-chain or branched-chain alkoxyl group having 1 to 16 carbonatoms. At least one of R³⁴ to R³⁷ represents an alkyl group having 3 ormore carbon atoms. “A” represents selected from the group consisting ofan acidic group, hydroxyl group, nitro group and halogen atom (—F, —Cl,—Br or I).

Specific examples of a basic compound (E2) are tetrabutylammoniumhydroxide, tetrapropylammonium hydroxide, tetrapentylammonium hydroxide,tetrahexylammonium hydroxide and the like. Among them,tetrabutylammonium hydroxide and tetrapropylammonium hydroxide arepreferred from the viewpoint of improving water solubility.

Such basic compounds (E2) may be used alone or in combination of two ormore in any proportion.

From the viewpoint of further enhancing coating properties of theconductive composition according to the fifth embodiment, the content ofa basic compound (E2) is preferred to be in a molar ratio of 1:0.1 to 1,more preferably 1:0.1 to 0.8, relative to 1 mol of a monomer unit havingat least one acidic group selected from the group consisting of sulfonicacid groups and carboxyl groups, which is one of the monomer units ofthe conductive polymer (A1). The ratio is especially preferred to be1:0.6 to 0.7, since in such content, properties of conductive coatingfilm are kept well and the acidic group of the conductive polymer (A1)is further stabilized.

Namely, the content of a basic compound (E2) in the conductivecomposition of the fifth embodiment is preferred to be 0.001 to 10 mass%, more preferably 0.01 to 5 mass %, relative to the total mass of theconductive composition.

The conductive composition of the fifth embodiment may further contain awater-soluble polymer (excluding the conductive polymer (A)).

The water-soluble polymer is a component that provides the conductivecomposition with properties to exhibit coating performance, film-formingperformance and film-forming capability on the resist layer, and worksas a surfactant.

A nonionic surfactant or the like is listed for a water-soluble polymer,namely, a surfactant. Particularly preferred is a water-soluble polymer(Z) having a nitrogen-containing functional group and a terminalhydrophobic group described in JP2002-226721A.

Unlike conventional surfactants, the water-soluble polymer (Z) exhibitssurface activity by a main-chain site (hydrophilic site) having anitrogen-containing functional group and by the terminal hydrophobicsite, and its effect of enhancing coating properties is high. Thus,without adding another surfactant, an excellent coating property isprovided for the conductive composition. Moreover, since thewater-soluble polymer (Z) does not contain acid or base, and byproductscaused by hydrolysis are less likely to be produced, adverse effects onthe resist layer or the like are lowered.

As the terminal hydrophobic group, the same examples described in thesurfactant (B) above are listed, and the preferred examples are thesame.

The terminal hydrophobic group of a water-soluble polymer (C) may beintroduced by any method as long as the effects of the present inventionare achieved. Usually, selecting a chain transfer agent for vinylpolymerization is preferred because of its easy process. In such a case,a chain transfer agent is not limited specifically as long as it iscapable of introducing a hydrophobic group such as below to the end of awater-soluble polymer: alkyl groups, aralkyl groups, aryl groups,alklylthio groups, aralkylthio groups and arylthio groups, each having 5to 100 carbon atoms. For example, to obtain a water-soluble polymerhaving an alkylthio group, aralkylthio group or arylthio group as itsterminal hydrophobic group, it is preferred to conduct vinylpolymerization using a chain transfer agent having a hydrophobic groupcorresponding to such a terminal hydrophobic group, for example, thiol,disulfide, thioether and the like. In particular, chain transfer agentssuch as n-dodecyl mercaptan and n-octyl mercaptan are preferred.

The main-chain structure (main-chain part) of a water-soluble polymer(Z) is not limited specifically as long as it is water soluble and is ahomopolymer of a vinyl monomer having a nitrogen-containing functionalgroup, or a copolymer of such a vinyl monomer and another vinyl monomer.

Examples of a vinyl monomer having a nitrogen-containing functionalgroup are acrylamides and their derivatives as well as heterocyclicmonomers having a nitrogen-containing functional group. Among them,those having an amide group are preferred. Specific examples areacrylamide, N,N-dimethylacrylamide, N-isopropylacrylamide,N,N-diethylacrylamide, N,N-dimethylaminopropylacrylamide,t-butylacrylamide, diacetone acrylamide, N,N′-methylene bisacrylamide,N-vinyl-N-methyl acrylamide, N-vinyl-2-pyrrolidone, N-vinylcaprolactam,and the like. Among them, acrylamides, N-vinyl-2-pyrrolidone andN-vinylcaprolactam are especially preferred.

For the other vinyl monomer, it is not limited specifically, as long asit is capable of copolymerizing with the vinyl polymer having anitrogen-containing functional group. Examples are styrene, acrylicacid, vinyl acetate, long-chain α-olefins and the like.

The main-chain part of the water-soluble polymer (Z) is water solubleand has a nitrogen-containing functional group. The number of units(degree of polymerization) in the main-chain part is preferred to be 2to 1000, more preferably 3 to 1000, especially preferably 5 to 10 in themolecule. If the number of units of the main-chain part having anitrogen-containing functional group is too great, surface activitytends to lower.

Regarding the main-chain part of a water-soluble polymer (Z) and theterminal hydrophobic part (for example, a part of alkyl group, aralkylgroup, aryl group, alkylthio group, aralkylthio group, or arylthiogroup), the molecular weight ratio (weight average molecular weight ofmain-chain part/weight average molecular weight of terminal hydrophobicgroup part) is preferred to be 0.3 to 170.

In the fifth embodiment, the content of a water-soluble polymer in theconductive composition, namely, the content of a surfactant, ispreferred to be 0.01 to 20 parts by mass, more preferably 0.01 to 15parts by mass, based on 100 parts by mass of a conductive polymer (A)solution or dispersion.

If the content of a surfactant is 0.01 parts by mass or more, effects asa surfactant (for example, effects of improving coating properties) areachieved sufficiently.

On the other hand, if the content exceeds 20 parts by mass, the effectsof improving coating properties reach their limit and simply result inan increase in cost.

In addition, the conductive composition of the fifth embodiment is morepreferred to contain a surfactant (B) above as a surfactant. Adding asurfactant (B) to the conductive composition of the fifth embodiment ispreferred since filtration results of the conductive composition areimproved.

Namely, yet another aspect of the conductive composition of the fifthembodiment is preferred to be: the conductive composition includes aconductive polymer (A), a basic compound (E2) and a surfactant (B); thebasic compound (E2) is a quaternary ammonium salt in which at least oneof the four groups bonded to a nitrogen atom is an alkyl group having 3or more carbon atoms; the surfactant (B) contains a water-solublepolymer (C) having a nitrogen-containing functional group and a terminalhydrophobic group; and the content of a compound (D1) with anoctanol/water partition coefficient (Log/Pow) of 4 or more in theconductive composition is 0.001 mass % or less, relative to the totalmass of the conductive composition.

In the fifth embodiment of the present invention, the content of thesurfactant (B) in the conductive composition is preferred to be 0.01 to50 mass %, more preferably 0.1 to 20 mass %, relative to the total massof the conductive composition.

In the surfactant (B) contained in the conductive composition of thefifth embodiment, a water-soluble polymer (C) may be the water-solublepolymer (C1) described in the third embodiment above.

Namely, another aspect of the conductive composition of the fifthembodiment is preferred to be: the conductive composition includes aconductive polymer (A), a basic compound (E2) and a surfactant (B); thebasic compound (E2) is a quaternary ammonium salt in which at least oneof the four groups bonded to a nitrogen atom is an alkyl group having 3or more carbon atoms; and a water-polymer (C) in the surfactant (B) is awater-soluble polymer (C1) having a nitrogen-containing functional groupand a terminal hydrophobic group and with the weight average molecularweight of 2000 or more.

Including the surfactant (B) containing a water-soluble polymer (C1) tothe conductive composition of the fifth embodiment is preferred sincecoating properties of the conductive composition improve and surfaceroughness of the conductive coating film is reduced. Also, such asetting is preferred since migration of components having low molecularweight of the surfactant from the conductor to the resist surface issuppressed, thus suppressing phenomena such as a reduction in the filmthickness of the resist layer.

In the fifth embodiment, when the surfactant (B) contains awater-soluble polymer (C1), the content of the surfactant (B) in theconductive composition is preferred to be 0.01 to 50 mass %, morepreferably 0.1 to 20 mass %.

(Other Components)

To enhance coating properties, the conductive composition of the fifthembodiment may contain alcohol or another surfactant other than the onementioned above within a scope that does not deviate from the effects ofthe present invention.

As for the alcohol, water-soluble alcohols are preferred; for example,methanol, ethanol, 2-propanol, 1-propanol, 1-butanol and the like may beused.

As for a surfactant, for example, fatty alcohols, alkylglycoside,polyalkyl glycol and the like may be used. Specific examples arealcohols having 8 to 20 carbon atoms.

(Method for Producing Conductive Composition of the Fifth Embodiment)

The conductive composition according to the fifth embodiment of thepresent invention is preferred to include a step for mixing a conductivepolymer (A), a basic compound (E2) and a surfactant as needed. A refinedconductive polymer (A1) described in the fourth embodiment above ispreferred to be used as a conductive polymer (A).

As described in the production method for a conductive polymer (A1) inthe fourth embodiment above, a refined conductive polymer (A1) isobtained by being dispersed or dissolved in an aqueous medium such aswater (hereinafter, such a conductive polymer (A1) is referred to as a“conductive polymer (A1) solution”). Thus, an aspect of the productionmethod of a conductive composition of the fifth embodiment is to producea conductive composition by a method that includes a step for adding abasic compound (E2) and a surfactant as needed (for example, thesurfactant (B) above) into a conductive polymer (A1) solution.

Conditions of adding a basic compound (E2) into a conductive polymer (A)solution are not limited specifically; a basic compound (E2) may beadded to a conductive polymer (A) solution at any selected temperatureand rate. However, it is preferred to keep a conductive polymer (A)solution at room temperature and to add a basic compound (E2) while themixture is being stirred.

In the present application, “room temperature” indicates 25° C.

If a conductive polymer (A) is solid, the solid conductive polymer (A),a basic compound (E2) and an aqueous medium and a surfactant (forexample, the surfactant (B) above) are combined as needed to produce aconductive composition. At that time, it is preferred to prepare aconductive polymer solution in advance by mixing a solid conductivepolymer (A) and an aqueous medium, and to add a basic compound (E2) anda surfactant as needed into the obtained conductive polymer solution.Namely, the method is preferred to include a step for preparing aconductive polymer (A) solution by mixing a solid conductive polymer (A)and an aqueous medium, and a step for adding a basic compound (E2) and asurfactant as needed into the conductive polymer (A) solution obtainedin the previous step.

As for the aqueous medium, water, a water-soluble organic solvent, or amixed solvent of water and water-soluble organic solvent may be used asdescribed above in the method for refining a conductive polymer (A).

(Effects)

The conductive composition according to the fifth embodiment of thepresent invention contains a basic compound (E2) in addition to aconductive polymer (A). The basic compound (E2) is capable of reactingwith residual monomers and sulfate ions more effectively to form stablesalts. Moreover, since the basic compound (E2) is also capable ofstabilizing the acidic group of the conductive polymer (A) (namely,stable salts are formed by the acidic group and the basic compound),elimination of the acidic group is suppressed when heat is applied.

The basic compounds described in Patent Literatures 2 to 6 can alsostabilize the acidic group of a conductive polymer (A) to a certaindegree, but due to their molecular weights or physical properties suchas strong base properties, those basic compounds are unable to fullystabilize acidic groups.

As described, the conductive composition of the fifth embodiment iscapable of forming a conductive coating film, from which acidicsubstances (residual monomers, sulfate ions, acidic groups eliminatedfrom conductive polymer (A) when heated) are less likely to migrate tothe resist layer.

Thus, especially when patterns are formed using a chemically amplifiedresist and by irradiating charged particle beams, migration of acidicsubstances to the resist layer is suppressed, thereby suppressingadverse effects such as a reduction in the film thickness of the resistlayer. Accordingly, the conductive composition of the fifth embodimentsufficiently satisfies properties required as the wiring ofsemiconductors has become finer in recent years.

In addition, since acidic substances (residual monomers, sulfate ions)have been removed in a conductive polymer (A) refined by ion-exchangemethods or the like, migration of acidic substances to the resist layeris suppressed effectively. Moreover, by refining a conductive polymer(A), basic substances (basic reaction auxiliary, ammonium ions) can alsobe removed, and migration of such basic substances to the resist layeris suppressed as well.

The conductive composition of the fifth embodiment contains a basiccompound (E2). Since a basic compound (E2) has both a hydrophilic partand a hydrophobic part, it also exhibits surface activity the same asthe water-soluble polymer, namely, the surfactant (B). Thus, theconductive composition of the fifth embodiment shows excellent coatingperformance without containing a surfactant. If it further contains asurfactant, coating properties are even more enhanced.

If the proportion of the conductive polymer (A) in the conductivecomposition of the fifth embodiment decreases, the proportion of acidicgroups that could be eliminated by heat will inevitably become smaller.Accordingly, the amount of acidic group migrating to the resist layerdecreases as well, thereby lowering adverse effects such as a reductionin the film thickness of the resist layer.

If the conductive composition contains a conductive polymer, namely, asurfactant, the relative proportion of the conductive polymer (A) in theconductive composition decreases. Accordingly, adverse effects such as areduction in the film thickness of the resist layer are lowered evenmore.

Another aspect of the conductive composition according to the fifthembodiment of the present invention is as follows: the conductivecomposition contains a conductive polymer (A), a basic compound (E2) andwater, wherein the basic compound (E2) is a quaternary ammonium salt inwhich at least one of four groups bonded to a nitrogen atom is an alkylgroup having 3 or more carbon atoms, based on the total mass of theconductive composition, the content of the conductive polymer (A) is0.01 to 30 mass %, the content of the basic compound (E2) is 0.001 to 10mass % and the content of water is 50 to 99.5 mass %; and the totalcontent of each component does not exceed 100 mass %.

Another aspect of the conductive composition of the fifth embodiment isas follows: the conductive composition contains a conductive polymer(A), a basic compound (E2) and water, wherein the conductive polymer (A)contains a monomer unit having at least one acidic group selected fromthe group consisting of sulfonic acid groups and carboxyl groups, thebasic compound (E2) is at least one compound selected from the groupconsisting of tetrabutylammonium hydroxide, tetrapropylammoniumhydroxide, tetrapentylammonium hydroxide and tetrahexylammoniumhydroxide, and the molar ratio of the basic compound (E2) to the monomerunit is 1:0.1 to 1:1.

Sixth Embodiment Conductive Composition

A conductive composition according to the sixth embodiment of thepresent invention contains a conductive polymer (A) and a basic compound(E3). The conductive composition is characterized by the following: theconductive polymer (A) contains a monomer unit having an acidic group,the basic compound (E3) has a basic group and two or more hydroxylgroups in the molecule, and with the melting point of 30° C. or more,and the content of the basic compound (E3) in the conductive compositionis 0.6 to 0.8 mol, relative to 1 mol of the monomer unit having anacidic group in conductive polymer (A).

In addition, the conductive composition is preferred to contain asurfactant (B).

Furthermore, the surfactant (B) is preferred to contain a water-solublepolymer (C) having a nitrogen-containing functional group and a terminalhydrophobic group, and in the conductive composition, the content of acompound (D1) with an octanol/water partition coefficient (Log Pow) of 4or more is preferred to be 0.001 mass % or less, relative to the totalmass of the conductive composition.

Also, the monomer unit having an acidic group in the conductive polymer(A) is preferred to be a monomer unit represented by the followinggeneral formula (1).

(In formula (1), R¹ to R⁴ each independently represents a hydrogen atom,a straight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. Also, at least one of R¹ to R⁴ represents an acidic groupor salt thereof)

The acidic group is preferred to be at least one acidic group selectedfrom the group consisting of sulfonic acid groups and carboxyl groups.

Namely, an aspect of the sixth embodiment of the present invention is asfollows:

[1] A conductive composition containing a conductive polymer (A) whichhas at least one acidic group selected from the group consisting ofsulfonic acid groups and carboxyl groups, and a basic compound (E3)which has a basic group and two or more hydroxyl groups in the moleculeand with the melting point of 30° C. or more, wherein the content of thebasic compound (E3) is 0.6 to 0.8 mol equivalent, relative to 1 mol of aunit, which has at least one acidic group selected from the groupconsisting of sulfonic acid groups and carboxyl groups, among the unitsforming the conductive polymer (A).

[2] The conductive composition described in [1], further containing awater-soluble polymer (excluding the conductive polymer (A)).

[3] The conductive composition described in [1] or [2], wherein theconductive polymer (A) has a monomer unit represented in the followinggeneral formula (1).

In formula (1), R¹ to R⁴ each independently represent a hydrogen atom, astraight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom. In addition, at least one of R¹ to R⁴ represents an acidicgroup. Here, an acidic group represents a sulfonic acid group or acarboxyl group.

[4] A conductive coating film formed by the conductive compositiondescribed in any one of [1] to [3].

The conductive composition according to the sixth embodiment of thepresent invention contains a conductive polymer (A) and a basic compound(E3). In addition, the conductive composition of the present embodimentis preferred to contain a surfactant (B).

The conductive polymer (A) and surfactant (B) in the conductivecomposition of the sixth embodiment are the same as the conductivepolymer (A) and the surfactant (B) contained in the conductivecomposition of the fifth embodiment described above. Thus, theirdescriptions are omitted here.

(Basic Compound (E3))

A basic compound (E3) has a basic group and two or more hydroxyl groupsin the molecule, and with the melting point of 30° C. or more.

When a compound has only a basic group in the molecule, it is difficultto efficiently form salts with the acidic group of the conductivepolymer (A). Thus, when heat is applied to the conductive polymer (A),the acidic group of the conductive polymer (A) tends to be eliminatedand the eliminated acidic group tends to migrate to the resist layer. Onthe other hand, if a compound has only hydroxyl groups in the molecule,salts are not formed with the acidic group of the conductive polymer(A). Also, if the number of hydroxyl groups in the molecule is one, orthe melting point is lower than 30° C., salts are not formed efficientlywith the acidic group either, due to insufficient fluidity or the likeof the compound in the conductive composition. Accordingly, the effectof suppressing migration of the acidic group to the resist layer is notsufficiently achieved.

The number of hydroxyl groups in a basic compound (E3) is preferred tobe 3 or more, considering the effect of suppressing migration of theacidic group to the resist layer, the ease of obtaining the compound,and processability. In addition, the upper limit of the number ofhydroxyl groups in a basic compound (E3) is preferred to be 8 or less,considering the ease of obtaining the compound. Namely, the number ofhydroxyl groups in a basic compound (E3) is preferred to be 2 to 8, morepreferably 3 to 6.

The melting point of a basic compound (E3) is preferred to be 50° C. ormore, more preferably 100° C. or more, even more preferably 150° C. ormore, considering the effect of suppressing migration of the acidicgroup to the resist layer.

Here, if the melting point of a basic compound (E3) is too high, it isdifficult to efficiently form salts with the acidic group because thedissolubility in a solvent is lowered or the like. Accordingly, theeffect of suppressing migration of the acidic group to the resist layeris less likely to be achieved sufficiently. Thus, considering the effectof suppressing migration of the acidic group to the resist layer, anddissolubility in a solvent, the melting point of a basic compound (E3)is preferred to be 300° C. or less, more preferably 250° C. or less,even more preferably 200° C. or less. Namely, the melting point of abasic compound (E3) is preferred to be 30 to 300° C., more preferably 40to 250° C., even more preferably 50 to 200° C.

Basic groups are those defined as Arrhenius bases, Bronsted bases, Lewisbases and the like, for example. Specific examples are ammonia and thelike.

The hydroxyl group may be in —OH or may be protected by a protectivegroup. Examples of protective groups are acetyl groups; silyl groupssuch as trimethylsilyl groups, t-butyl dimethylsilyl groups; acetalprotective groups such as methoxymethyl groups, ethoxymethyl groups andmethoxyethoxymethyl groups; benzoyl groups; alkoxide groups and thelike.

Examples of a basic compound (E3) are 2-amino-1,3-propanediol,tris(hydroxymethyl)aminomethane, 2-amino-2-methyl-1,3-propanediol,2-amino-2-ethyl-1,3-propanediol,3-[N-tris(hydroxymethyl)methylamino]-2-hydroxypropansulfonic acid,N-tris(hydroxymethyl)methyl-2-aminoethane sulfonic acid and the like.Among those, tris(hydroxymethyl)aminomethane is preferred from theviewpoint of excellent solubility and basic properties.

Those compounds may be used alone or in combination of two or more inany proportion.

The content of a basic compound (E3) in the conductive compositionaccording to the sixth embodiment of the present invention is 0.6 to 0.8mol to 1 mol of a monomer unit having at least one acidic group selectedfrom the group consisting of sulfonic acid groups and carboxyl groups,among the monomer units in the conductive polymer (A).

Namely, if the molar ratio of a basic compound (E3) to the monomer unitis 1:0.6 to 1:0.8, the acidic group in the conductive polymer (A) isstabilized. Especially, the content of a basic compound (E3) to 1 mol ofthe monomer unit is preferred to be 0.65 to 0.75 mol, that is, the molarratio of 1:0.65 to 1:0.75, since the acidic group in the conductivepolymer (A) is especially stabilized at such a ratio.

Namely, the content of a basic compound (E3) in the conductivecomposition of the sixth embodiment is preferred to be 0.001 to 10 mass%, more preferably 0.01 to 5 mass %, relative to the total mass of theconductive composition.

In addition, the content of a conductive polymer (A) in the conductivecomposition of the sixth embodiment is preferred to be 0.01 to 30 mass%, more preferably 0.05 to 10 mass %, relative to the total mass of theconductive composition.

(Other Components)

To enhance coating properties, the conductive composition of the sixthembodiment may contain alcohol or another surfactant other than thesurfactant (B) above within a scope that does not deviate from theeffects of the present invention. Those alcohols and surfactants are thesame as the other components contained in the conductive composition ofthe first embodiment described above.

(Method for Producing Conductive Composition of the Sixth Embodiment)

The conductive composition according to the sixth embodiment of thepresent invention is obtained by using a basic compound (E3) instead ofa basic compound (E2) in the production method of a conductivecomposition described above in the fifth embodiment.

(Effects)

The conductive composition according to the sixth embodiment of thepresent invention includes a basic compound (E3) in addition to aconductive polymer (A). The basic compound (E3) is capable of reactingwith residual monomers and sulfate ions more effectively to form stablesalts. Moreover, since the basic compound (E3) is also capable ofstabilizing the acidic group of the conductive polymer (A) (namely,capable of forming stable salts from an acidic group and the basiccompound), elimination of acidic groups caused by heat is suppressed.

As described, the conductive composition of the sixth embodiment iscapable of forming a conductive coating film in which acidic substances(residual monomers, sulfate ions, acidic groups eliminated fromconductive polymer (A) when heated) are less likely to migrate to theresist layer.

Thus, especially when patterns are formed using a chemically amplifiedresist and by irradiating charged particle beams, migration of acidicsubstances to the resist layer is suppressed, thereby suppressingadverse effects such as a reduction in the film thickness of the resistlayer. Accordingly, the conductive composition of the sixth embodimentsufficiently satisfies the properties required as the wiring ofsemiconductors has become finer in recent years.

In addition, since acidic substances (residual monomers, sulfate ions)have been removed in a conductive polymer (A) refined by ion-exchangemethods or the like, migration of acidic substances to the resist layeris suppressed effectively. Moreover, by refining a conductive polymer(A), basic substances (basic reaction auxiliary, ammonium ions) are alsoremoved, and migration of such basic substances to the resist layer issuppressed as well.

Moreover, if a surfactant (B) is further contained, coating propertieswill be even more enhanced, while the relative ratio of the conductivepolymer (A) in the conductive composition is reduced. Thus, adverseeffects such as a reduction in the film thickness of the resist layerare further lowered.

(Usage Purposes)

The conductive compositions of the fifth and sixth embodiments are usedfor a conductive coating film applied on a resist surface especially ina pattern-forming method using chemically amplified resist and chargedparticle beams, and for capacitors, transparent electrodes,semiconductor materials and the like.

Among them, when the conductive composition is used for forming aconductive coating film on a resist surface in a pattern-forming methodusing chemically amplified resist and by irradiating charged particlebeams, after the conductive composition of the fifth or six embodimentof the present invention is coated on the resist surface by a coatingmethod, patterns are formed by irradiating charged particle beams.Accordingly, migration of acidic substances from the conductivecomposition to the resist layer is suppressed, and desired resistpatterns are formed.

(Conductive Coating Film)

Using the conductive compositions of the fifth or sixth embodiment ofthe present invention, a conductive coating film is formed by applyingthe conductive composition on a resist layer formed on a silicon wafer,quartz mask substrate and the like and by drying the film. Examples of acoating method are gravure coater, roll coater, curtain-flow coater,spin coater, bar coater, reverse coater, kiss coater, fountain coater,rod coater, air doctor coater, knife coater, blade coater, castingcoater and screen coater; a spray method of spray coating; and immersionmethods such as dipping. Among those, spin coating is preferred.

(Effects)

A conductive coating film formed by the conductive composition accordingto the fifth or the sixth embodiment is capable of lowering orsuppressing migration of acidic substances to the resist layer. Thus, areduction in the film thickness or the like of the resist layer issuppressed.

Another aspect of the conductive composition of the sixth embodiment ofthe present invention is as follows: a conductive composition contains aconductive polymer (A), a basic compound (E3), and water, wherein theconductive polymer (A) contains a monomer unit having an acidic group;the basic compound (E3) is at least one compound selected from the groupconsisting of 2-amino-1,3-propanediol, tris(hydroxymethyl)aminomethane,2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol,3[N-tris(hydroxymethyl)methylamino]-2-hydroxypropane sulfonic acid, andN-tris(hydroxymethyl)methyl-2-aminoethane sulfonic acid, the content ofthe basic compound (E3) in the conductive composition is 0.6 to 0.8 mol,relative to 1 mol of a monomer unit having an acidic substituent of theconductive polymer (A), and the proportion of the conductive polymer (A)is 0.01 to 30 mass %, relative to the total mass of the conductivecomposition.

In addition, another aspect of the conductive composition of the sixthembodiment is as follows: a conductive composition contains a conductivepolymer (A), a basic compound (E3), a surfactant (B) and water, whereinthe conductive polymer (A) contains a monomer unit having an acidicgroup; the basic compound (E3) is at least one compound selected fromthe group consisting of 2-amino-1,3-propanediol,tris(hydroxymethyl)aminomethane, 2-amino-2-methyl-1,3-propanediol,2-amino-2-ethyl-1,3-propanediol,3-[N-tris(hydroxymethyl)methylamino]-2-hydroxypropane sulfonic acid, andN-tris(hydroxymethyl)methyl-2-aminoethane sulfonic acid, the surfactant(B) contains a water-soluble polymer (C) having a nitrogen-containingfunctional group and a terminal hydrophobic group, the content of acompound (D1) with an octanol/water partition coefficient (Log Pow) of 4or more in the conductive composition is 0.001 mass % or less, relativeto the total mass of the conductive composition, based on the total massof the conductive composition, the content of the conductive polymer (A)is 0.01 to 30 mass %, the content of the basic compound (E3) is 0.001 to10 mass %, the content of the surfactant (B) is 0.01 to 50 mass % andthe content of water is 50 to 99.5 mass %; and the total content of eachcomponent does not exceed 100 mass %.

<Laminate According to the Seventh Embodiment of the Present Invention>

A laminate according to the seventh embodiment of the present inventionhas a substrate, a conductive coating film and an electron-beam resistfilm, wherein the electron-beam resist film is laminated on thesubstrate, and the conductive coating film is laminated on theelectron-beam resist film, the surface resistance value of the laminateis 5×10¹⁰Ω/□ or less, the surface roughness (Ra1 value) of theconductive coating film measured by a stylus profiler is 0.7 nm or less,the surface roughness (Ra2 value) of the conductive coating filmmeasured by an optical microscope is 0.35 nm or less, and the conductivecoating film is formed with a conductive composition containing aconductive polymer (A).

FIG. 2 is a cross-sectional view showing an example of the laminateaccording to the seventh embodiment of the present invention. Laminate20 has a structure where electron-beam resist layer 21 is laminated onsubstrate 11, and conductive coating film 12 is laminated on theelectron-beam resist layer.

For the sake of description, measurement ratios in FIG. 2 are differentfrom actual ratios.

The same substrate as that described in the first embodiment above maybe used here. In addition, as for the conductive composition containinga conductive polymer (A), those described in the second through sixthembodiments above are preferred.

Regarding a conductive coating film of the laminate, the surfaceroughness (Ra1 value) measured by a stylus profiler and the surfaceroughness (Ra2 value) measured by an optical microscope are measured byemploying the measurement methods respectively described in the firstembodiment above. The preferred range of the Ra1 values and Ra2 valuesare the same as those described in the first embodiment above.

(Method for Forming Laminate of the Seventh Embodiment)

A method for forming a laminate of the seventh embodiment of the presentinvention is preferred to include step (1) for forming an electron-beamresist film by coating electron-beam resist on at least one surface of asubstrate and by drying the resist, and step (2) for forming aconductive coating film on the electron-beam resist film by coating aconductive composition containing a conductive polymer (A) and by dryingthe composition.

(Step (1))

A method for coating electron-beam resist on at least one surface of asubstrate is not limited specifically as long as the effects of thepresent invention are achieved. For example, preferred methods are spincoating, spray coating, dip coating, roll coating, gravure coating,reverse coating, roll brushing, air knife coating and curtain coatingmethods and the like. Among them, spin coating is preferred because ofthe ease of processing.

In addition, an electron-beam resist film is formed by coatingelectron-beam resist on a substrate surface using the above coatingmethod, and then by applying heat at a temperature recommended for theresist.

The electron-beam resist is not limited specifically as long as theeffects of the present invention are achieved. A chemically amplifiedresist, for example, FEP-171 resist made by FUJIFILM Arch Co. Ltd., maybe used.

(Step (2))

A conductive composition containing a conductive polymer (A) is coatedon the electron-beam resist film obtained by step (1), and thecomposition is dried. Accordingly, a laminate of the seventh embodimentis formed.

Examples of a method for coating a conductive composition on theelectron-beam resist film are the same as those listed as coatingmethods. Preferred examples are the same as well.

After a conductive coating film is formed by coating a conductivecomposition, the substrate is kept at 25° C. for 10 to 60 minutes orheat treatment is conducted on the substrate so that a laminate isformed.

When heat is applied, the treatment is preferred to be conducted at 60to 90° C. for 1 to 5 minutes, more preferably at 70 to 80° C. for 1 to 3minutes.

The film thickness of a conductive coating film formed in step (2) ispreferred to be 1 to 100 nm, more preferably 3 to 60 nm, especiallypreferably 5 to 30 nm.

Regarding the laminate of the seventh embodiment, the surface resistancevalue of the laminate is 5×10¹⁰Ω/□ or less, the surface roughness (Ra1value) of the conductive coating film measured by a stylus profiler is0.7 nm or less, and the surface roughness (Ra2 value) of the conductivecoating film measured by an optical microscope is 0.35 nm or less.Accordingly, the laminate is applicable to a next-generation process forsemiconductor devices.

EXAMPLES

In the following, the present invention is described in further detailby referring to examples. However, the following examples do not limitthe scope of the present invention. In addition, “%” in the followingexamples indicates “mass %.”

First, examples of the first embodiment of the present invention aredescribed.

<Evaluation of Molecular Weight>

For each of a water-soluble polymer (C) and a water-soluble polymer(C1), 0.1 wt % solution was filtrated through a 0.45 μm-membrane filterto prepare a sample. The sample was measured by GPC under conditionsbelow to evaluate weight average molecular weights of the water-solublepolymer (C) and water-soluble polymer (C1) respectively.

-   -   Measuring instrument: TOSOH GPC-8020 (made by Tosoh Corporation)    -   Eluent: 0.2M-NaNO₃-DIW/acetonitrile=80/20 (v/v)    -   Column temperature: 30° C.    -   Calibration curve: created using EasiVial™ polyethylene        glycol/oxide (made by Polymer Lab Inc.)

<Evaluation of Conductivity: Conductor>

The surface resistance [Ω] of a conductive coating film was measured bya 2-terminal method (distance between electrodes at 20 mm) using HirestaMCP-HT260 (made by Mitsubishi Chemical Corporation).

<Evaluation of Conductivity: Laminate>

A laminate was obtained by the following procedure:

Chemically amplified electron-beam resist (for example, commerciallyavailable positive type resist FEP-171 made by FUJIFILM ElectronicMaterials Co., Ltd., hereinafter referred to as “resist”) wasspin-coated (2000 rpm×60 seconds) on a 4 cm×4 cm glass plate, and heatwas applied using a hot plate at 130° C. for 2 minutes to form a coatingfilm with an approximate film thickness of 200 nm; then, after aconductive composition was spin-coated (2000 rpm×60 seconds), heat wasapplied using a hot plate at 80° C. for 2 minutes to form a conductivecoating film with an approximate film thickness of 20 nm. The surfaceresistance [Ω] of the laminate was measured by a 2-terminal method(distance between electrodes at 20 mm) using Hiresta MCP-HT260 (made byMitsubishi Chemical Corporation).

<Evaluation of Surface Roughness>

After a conductive composition was spin-coated (2000 rpm×60 seconds) ona 4-inch silicon wafer, heat was applied using a hot plate at 80° C. for2 minutes to form a conductor with an approximate film thickness of 20nm.

(Ra1 Value)

The surface roughness (Ra1 value, [nm]) of the obtained conductor wasmeasured using a stylus profiler (Stylus Profiler P-16+, made by KLATencor Corporation).

-   -   Stylus: 2 um R60°    -   Needle pressure: 0.03 mg    -   Scanning range: 500 um    -   Scanning speed: 2 um/s

(Ra2 Value)

The surface roughness (Ra2 value, [nm]) of the obtained conductor wasmeasured using an optical microscope (Olympus OLS 3500).

-   -   Measurement mode: dynamic    -   Scanning range: 1000 nm    -   Scanning speed: 0.3 Hz    -   I Gain: 1000    -   Sensor lever: Olympus OMCL-AC240TS-C2

<Measuring Glass Transition Temperature>

Using 5 mg of powdered water-soluble polymer (C) or water-solublepolymer (C1), DSC was measured under the conditions below and the glasstransition temperature of a water-soluble polymer (C) or a water-solublepolymer (C1) was evaluated.

-   -   Measuring instrument: Thermoplus EV0 DSC8230 (made by Rigaku        Corporation)    -   Atmosphere: nitrogen    -   Flow rate: 50 mL/min    -   Rate of temperature rise: 150° C. (10° C./min), 20° C. (50°        C./min), 150° C. (10° C./min)    -   Reference: alumina

<Content of Compound (D1) Having Log Pow of 4 or More>

A water-soluble polymer (C) or a water-soluble polymer (C1) was dilutedby acetone and subjected to analysis by gas chromatography under theconditions below. The structure of the observed peaks was identified,and a Log Pow was calculated by Chem Draw Pro 12.0 made by CambridgeSoft. Then, regarding a compound (D1) having a Log Pow of 4 or more, itscontent in terms of n-dodecyl mercaptan was determined using an internalstandard method by gas chromatography.

-   -   Measuring conditions    -   Instrument: model 6890 N, made by Agilent Technologies, Inc.    -   Detector: 5973 Mass Selective Detector    -   Column: UA-5 (30 m×0.25 mm×0.25 μm) made by Frontier        Laboratories Ltd.    -   Conditions to raise GC temperature: 40° C. (1 min. hold), 5°        C./min to 300° C. (5 min. hold)    -   GC inlet temperature: 160 [° C.]    -   Carrier gas: He, flow rate of 1 [mL/min]    -   Split ratio: 20/1    -   MS ion source temperature: 230° C.    -   MS quadruple temperature: 150° C.    -   Ionization method: electron ionization (ionization voltage: 70V)

<Evaluation by Film Reduction Test>

(Reduction in the Film Thickness of the Resist)

A reduction in the film thickness of a resist was evaluated as follows.

(1) forming resist film: after 0.4 um of chemically amplified resist wasspin-coated at 2000 rpm/60 seconds on a 4-inch silicon wafer(substrate), the solvent was removed through prebake at 130° C. for 90seconds.

(2) measuring thickness of resist film: part of the resist formed on thesubstrate was peeled to measure the initial resist film thickness (A)(nm) based on the substrate surface using a stylus profiler (StylusProfiler P-16+, made by KLA-Tencor Corporation).

(3) forming conductive coating film: on the resist surface coated on thesubstrate, after 2 mL of conductive compositions of the second to sixthembodiments were each dropped so as to cover the entire resist surface,the composition was spin-coated at 2000 rpm/60 seconds using a spincoater. Accordingly, a conductive coating film with a film thickness of30 nm was obtained.

(4) baking: the substrate with laminated resist and conductive coatingfilm was heated on a hot plate under air atmosphere at 120° C. for 20minutes, and then the substrate was kept under air atmosphere at roomtemperature (25° C.) for 90 seconds.

(5) washing with water: after the conductive coating film was washedaway with 20 mL of water, the substrate was rotated at 2000 rpm/60seconds using a spin coater to remove the water on the resist surface.

(6) developing: 20 mL of a developing solution made of a solutioncontaining 2.38 mass % tetramethylammonium hydroxide (TMAH) was droppedon the resist surface. After the substrate was kept standing for 60seconds, the developing solution was removed by spin coating thesubstrate at 2000 rpm, and was dried by maintaining the rotation for 60seconds.

(7) After removing part of the resist positioned within 5 mm from theportion where part of the resist was peeled in step (2) above, resistfilm thickness (B) (nm) was measured after development using a stylusprofiler.

(8) A reduction in the film thickness (C) of the resist (C=A−B) wascalculated by subtracting (B) from the value (A) above.

(Standard Reduction in Film Thickness)

Each resist has a reduction in film thickness (D) (nm) specific to astorage period after the resist film is formed (hereinafter referred toas a standard reduction in film thickness). Such a reduction in filmthickness (D) unrelated to conductive coating film was measured inadvance as follows.

(1) forming resist film: after 0.4 um of chemically amplified resist wasspin-coated at 2000 rpm/60 seconds on a 4-inch silicon wafer(substrate), the solvent was removed through prebake at 130° C. for 90seconds.

(2) measuring thickness of resist film: part of the resist formed on thesubstrate was peeled to measure the initial resist film thickness (E)(nm) by a stylus profiler based on the substrate surface.

(3) baking: the substrate with laminated resist was heated on a hotplate under air atmosphere at 120° C. for 20 minutes, and then thesubstrate was kept standing under air atmosphere at room temperature(25° C.) for 90 seconds.

(4) developing: 20 mL of a developing solution made of a solutioncontaining 2.38 mass % TMAH solution was dropped on the resist surface.After the substrate was kept standing for 60 seconds, the developingsolution was removed by spin coating the substrate at 2000 rpm, and wasdried by maintaining the rotation for 60 seconds.

(5) After removing part of the resist positioned within 5 mm from theportion where part of the resist was peeled in step (2) above, resistfilm thickness (F) (nm) was measured after development using a stylusprofiler.

(6) A standard reduction in film thickness (D) of the resist (D=F−E) wascalculated by subtracting (E) from the value (F) above.

<Evaluation of Crystalline Impurity>

The surface of a laminate was observed with a magnification of 1000times using an industrial microscope (Nikon Eclipse LV 100).

Production Example 1A Producing Conductive Polymer Solution (A-1)

A monomer solution was obtained by dissolving 1 mol of3-aminoanisole-4-sulfonic acid at 0° C. in 300 mL of a pyridine solutionof a 4 mol/L concentration (solvent: water/acetonitrile=3/7). Meanwhile,an oxidizing agent solution was prepared by dissolving 1 mol of ammoniumperoxodisulfate in 1 L of a water/acetonitrile=3/7 solution. Next, themonomer solution was dropped while the oxidizing agent solution wascooled at 5° C. After the dropping was completed, the mixture wasfurther stirred at 25° C. for 12 hours, and a conductive polymer wasobtained. Then, the reaction mixture containing the conductive polymerwas filtrated by a centrifugal separator. Further, the mixture waswashed with methanol and dried. Accordingly, 185 grams of powderedconductive polymer (A-1) was obtained.

Production Example 2A Producing Conductive Polymer Solution (A1-1)

20 grams of conductive polymer (A-1) obtained in production example 1Aabove was dissolved in a mixed solvent of 940 grams of pure water and 40grams of 2-propanol. Accordingly, 1000 grams of a conductive polymersolution (A1-1) with a solid content of 2 mass % was obtained.

500 mL of cationic ion exchange resin washed with ultrapure water(“Amberlite IR-120B” made by Organo Chemical Co., Ltd.) was filled in acolumn.

Then, 1000 grams of the conductive polymer solution (A1-1) was passedthrough the column at a speed of 50 mL/min (SV=6), and 900 grams of aconductive polymer solution (A1-1) from which basic substances or thelike were removed was obtained.

Next, 500 mL of anionic ion exchange resin washed with ultrapure water(“Amberlite IRA410” made by Organo Chemical Co., Ltd.) was filled in acolumn.

Then, 900 grams of the conductive polymer solution (A1-1) was passedthrough the column at a speed of 50 mL/min (SV=6), and 800 grams of aconductive polymer solution (A1-1-1) from which basic substances or thelike were removed was obtained.

When composition analysis was conducted on the conductive polymersolution (A1-1) by ion chromatography, 80% of residual monomers, 99% ofsulfate ions and 99% or more of basic substances were found to have beenremoved.

Here, 1 sverdrup (SV) is defined as 1×106 m³/s (1 GL/s).

Production Example 3A Producing Water-Soluble Polymer (C-1)

A reaction mixture was obtained by dissolving 55 grams ofN-vinylpyrrolidone as a vinyl monomer having a nitrogen-containingfunctional group, 3 grams of azobisisobutyronitrile as a polymerizationinitiator, and 1 gram of n-dodecyl mercaptan as a chain transfer agentfor introducing a terminal hydrophobic group into 100 mL of isopropylalcohol as a solvent while the mixture was stirred. Next, in 100 mL ofisopropyl alcohol heated to 80° C. in advance, the reaction mixture wasdropped at a dropping speed of 1 mL/min to conduct droppingpolymerization. The dropping polymerization was conducted whileisopropyl alcohol was retained at 80° C. After the dropping wascompleted, the reactant solution was further aged at 80° C. for 2 hoursand cooled. Then, the solution was vacuum concentrated, and theresultant reaction product was dissolved again in a small amount ofacetone. The acetone solution of the reaction product was dropped into alarge amount of n-hexane. The resultant white precipitate was filtrated,washed with n-hexane and dried. Accordingly, 45 grams of a water-solublepolymer (C-1) was obtained. [water-soluble polymer (C1-1): weightaverage molecular weight: 1300, terminal hydrophobic group: alkylthiogroup having 12 carbon atoms; glass transition temperature: 51° C.]

Production Example 4A Producing Water-Soluble Polymer (C-2)

A reaction mixture was obtained by dissolving 55 grams ofN-vinylpyrrolidone as a vinyl monomer having a nitrogen-containingfunctional group, 3 grams of azobisisobutyronitrile as a polymerizationinitiator, and 1 gram of n-dodecyl mercaptan as a chain transfer agentfor introducing a terminal hydrophobic group into 100 mL of isopropylalcohol as a solvent while the mixture was being stirred. Next, in 100mL of isopropyl alcohol heated to 80° C. in advance, the reactionmixture was dropped at a dropping speed of 1 mL/min to conduct droppingpolymerization. The dropping polymerization was conducted whileisopropyl alcohol was retained at 80° C. After the dropping wascompleted, the reactant solution was further aged at 80° C. for 2 hours.Then the solution was cooled and vacuum concentrated to obtain a whitemixture of water-soluble polymer (C-2). The water-soluble polymer (C-2)contained 1-pyrrolidine-2-onyl group as the nitrogen-containingfunctional group and a dodecyl group as the terminal hydrophobic group.Also, in the water-soluble polymer (C-2), as the compound (D1) having aLog Pow of 4 or more, 2-(dodecylthio)-2-methylbutyronitrile (Log Pow of6.5) was contained at 1.9 parts by mass based on 100 parts by mass ofthe water-soluble polymer (C-2), namely, at 1.9 mass % of the total massof the water-soluble polymer (C-2).

Production Example 5A Producing Water-Soluble Polymer (C1-1)

A reaction mixture was obtained by dissolving 55 grams ofN-vinylpyrrolidone as a vinyl monomer having a nitrogen-containingfunctional group, 2 grams of azobisisobutyronitrile as a polymerizationinitiator, and 0.6 grams of n-dodecyl mercaptan as a chain transferagent for introducing a terminal hydrophobic group into 100 mL ofisopropyl alcohol as a solvent while the mixture was being stirred.Next, in 100 mL of isopropyl alcohol heated to 80° C. in advance, thereaction mixture was dropped at a dropping speed of 1 mL/min to conductdropping polymerization. The dropping polymerization was conducted whileisopropyl alcohol was retained at 80° C. After the dropping wascompleted, the reactant solution was further aged at 80° C. for 2 hoursand cooled. Then, the solution was vacuum concentrated, and theresultant reaction product was dissolved again in a small amount ofacetone. The acetone solution of the reaction product was dropped into alarge amount of n-hexane. The resultant white precipitate was filtrated,washed with n-hexane and dried. Accordingly, 45 grams of a water-solublepolymer (C1-1) was obtained. [water-soluble polymer (C1-1): weightaverage molecular weight: 2000, terminal hydrophobic group: alkylthiogroup having 12 carbon atoms; glass transition temperature: 73° C.]

Production Example 6A Producing Water-Soluble Polymer (C1-2)

A reaction mixture was obtained by dissolving 55 grams ofN-vinylpyrrolidone as a vinyl monomer having a nitrogen-containingfunctional group, 1 gram of azobisisobutyronitrile as a polymerizationinitiator, and 0.15 gram of n-dodecyl mercaptan as a chain transferagent for introducing a terminal hydrophobic group into 100 mL ofisopropyl alcohol as a solvent while the mixture was being stirred.Next, in 100 mL of isopropyl alcohol heated to 80° C. in advance, thereaction mixture was dropped at a dropping speed of 1 mL/min to conductdropping polymerization. The dropping polymerization was conducted whileisopropyl alcohol was retained at 80° C. After the dropping wascompleted, the reactant solution was further aged at 80° C. for 2 hoursand cooled. Then, the solution was vacuum concentrated, and theresultant reaction product was dissolved again in a small amount ofacetone. The acetone solution of the reaction product was dropped into alarge amount of n-hexane. The resultant white precipitate was filtrated,washed with n-hexane and dried. Accordingly, 45 grams of a water-solublepolymer (C1-2) was obtained. [water-soluble polymer (C1-2): weightaverage molecular weight: 2900, terminal hydrophobic group: alkylthiogroup having 12 carbon atoms; glass transition temperature: 110° C.]

Production Example 7A Producing Water-Soluble Polymer (C1-3)

A reaction mixture was obtained by dissolving 55 grams ofN-vinylpyrrolidone as a vinyl monomer having a nitrogen-containingfunctional group, 0.5 gram of azobisisobutyronitrile as a polymerizationinitiator, and 0.1 gram of n-dodecyl mercaptan as a chain transfer agentfor introducing a terminal hydrophobic group into 100 mL of isopropylalcohol as a solvent while the mixture was being stirred. Next, in 100mL of isopropyl alcohol heated to 80° C. in advance, the reactionmixture was dropped at a dropping speed of 1 mL/min to conduct droppingpolymerization. The dropping polymerization was conducted whileisopropyl alcohol was retained at 80° C. After the dropping wascompleted, the reactant solution was further aged at 80° C. for 2 hoursand cooled. Then, the solution was vacuum concentrated, and theresultant reaction product was dissolved again in a small amount ofacetone. The acetone solution of the reaction product was dropped into alarge amount of n-hexane. The resultant white precipitate was filtrated,washed with n-hexane and dried. Accordingly, 45 grams of a water-solublepolymer (C1-3) was obtained. [water-soluble polymer (C1-3): weightaverage molecular weight: 6150, terminal hydrophobic group: alkylthiogroup having 12 carbon atoms; glass transition temperature: 114° C.]

Using conductive polymers and water-soluble polymers obtained inproduction examples 1A to 7A, conductive compositions were respectivelyprepared as shown in Table 1.

TABLE 1 conductive composition 1A 2A 3A 4A 5A conductive polymer (A-1) 11 1 1 1 [part by mass] (A1-1) — — — — — water-soluble (C-1) 1 0.98 0.920.8 — polymer (C-2) — 0.02 0.08 0.2 1 [part by mass] (C1-1) — — — — —(C1-2) — — — — — (C1-3) — — — — — water [part by mass] 100 100 100 100100

Examples 1 to 2, Comparative Examples 1 to 3

Conductors were formed by respectively using conductive compositions(1A) to (5A) shown in Table 1.

More specifically, after each conductive composition was spin-coated ona 4-inch silicon wafer (2000 rpm×60 seconds), heat was applied at 80° C.for 2 minutes on a hot plate to form a conductive coating film with athickness of 20 nm. Accordingly, a conductor was obtained. The surfaceresistance value, surface roughness (Ra1 value), content of compound(D1), presence of crystals, and adverse effect of crystals on resistwere evaluated according to the evaluation methods described above. Theresults are shown in Table 2.

TABLE 2 comp. comp. comp. example 1 example 2 example 1 example 2example 3 conductive composition 1A 2A 3A 4A 5A content of compound (D1)[mass %] 0.0006 0.001 0.002 0.004 0.019 Ra1 value [nm] 0.56 0.54 0.920.93 1.65 Ra2 value [nm] 0.259 0.261 0.265 0.26 0.258 surface resistance[Ω/□] 1.00E+09 1.00E+09 1.00E+09 1.00E+09 1.00E+09 presence of crystalsno no yes yes yes adverse effect on resist of crystals none none mediummedium significant

From the results shown in Table 2, in examples 1 and 2, namely, when thecontent of a compound (D1) is 0.001 mass % or less, no crystals wereobserved on the coating film, and it was found that adverse effects onthe resist were suppressed.

Next, examples of the conductive composition according to the thirdembodiment of the present invention are described.

<Evaluation of Conductivity>

The conductive composition was spin-coated (2000 rpm×60 seconds) on aglass substrate, to which heat was applied on a hot plate at 80° C. for2 minutes. Accordingly, a conductor (sample piece 1) was formed with acoating film having an approximate film thickness of 30 nm formed on theglass substrate.

The surface resistance value [Ω] of sample piece 1 was measured by atwo-terminal method (distance between electrodes at 20 mm) using HirestaMCP-HT260 (made by Mitsubishi Chemical).

<Surface Roughness>

The same method described in the examples of the first embodiment wasemployed to measure surface roughness (Ra1 value and Ra2 value).

<Reduction in Film Thickness>

The same method described in the examples of the first embodiment wasemployed to measure a reduction in the film thickness of the resist.

Using conductive polymers and water-soluble polymers obtained inproduction examples 1A to 7A, conductive compositions were respectivelyprepared as shown in Table 3.

TABLE 3 conductive composition 1B 2B 3B 4B conductive (A-1) 0.7 0.7 0.70.7 polymer (A1-1) — — — — water-soluble (C-1) — — — 0.3 polymer (C-2) —— — — [part by mass] (C1-1) 0.3 — — — (C1-2) — 0.3 — — (C1-3) — — 0.3 —water [part by mass] 100    100    100    100   

Examples 3 to 5

Using conductive compositions (1B) to (3B) shown in Table 3,conductivity and surface roughness evaluations and evaluation by filmreduction testing were respectively performed according to theevaluation methods described above. The results are shown in Table 4.

Comparative Example 4

Using the conductive composition (4B) shown in Table 3, conductivity,surface roughness and impact on resist were evaluated according to theevaluation methods described above. The results are shown in Table 4.

TABLE 4 comp. example 3 example 4 example 5 example 4 conductivecomposition 1B 2B 3B 4B added base Py Py Py Py water-soluble polymerC1-1 C1-2 C1-3 C-1 Ra1 value [nm] 0.5 0.53 0.52 0.61 Ra2 value [nm]0.324 0.304 0.28 0.371 surface resistance 2.00E+07 2.00E+07 2.00E+072.00E+07 [Ω/□] reduction in film 3 3 3 4 thickness [nm]

In examples 3 to 5 prepared by combining a conductive polymer (A-1) andwater-soluble polymers (C1-1) to (C1-3) each with a weight averagemolecular weight of 2000 or more, excellent results were obtained inboth surface roughness and reduction in film thickness, compared withcomparative example 4 which is prepared by combining a conductivepolymer (A-1) and a water-soluble polymer (C1) with a weight averagemolecular weight of 1300.

From the above results, it was found that the conductive composition ofthe third embodiment, which contains a water-soluble polymer (C1) havinga nitrogen-containing functional group and a terminal hydrophobic groupand has a weight average molecular weight of 2000 or more, exhibitsexcellent coating properties and conductivity and is capable of forminga conductive coating film with excellent surface roughness and a lessreduction in the film thickness of a laminate such as resist coated on asubstrate.

Next, examples of the conductive composition according to the fourthembodiment of the present invention are described.

<Evaluation of Conductivity>

The same method described in the examples of the third embodiment wasemployed to evaluate conductivity.

<Surface Roughness>

The same method described in the examples of the third embodiment wasemployed to measure surface roughness (Ra1 value and Ra2 value).

<Reduction in Film Thickness>

The same method described in the examples of the third embodiment wasemployed to measure reduction in the film thickness of the resist.

Production Example 8A Producing Water-Soluble Polymer (C-3)

In isopropyl alcohol heated to 80° C. in advance, 55 grams ofN-vinylpyrrolidone, 3 grams of isobutyronitrile as a polymerizationinitiator and 1 gram of n-dodecyl mercaptan as a chain transfer agentwere dropped while the internal temperature was maintained at 80° C. toconduct dropping polymerization. After the dropping was completed, thereaction mixture was further aged at 80° C. for 2 hours, cooled, vacuumconcentrated and dissolved again in a small amount of acetone. Theacetone solution of the polymer was dropped into a large amount ofn-hexane. The resultant white precipitate was filtrated, washed anddried. Accordingly, 45 grams of a water-soluble polymer (C-3) wasobtained. The weight average molecular weight of the water-solublepolymer (C-3) was 1300. In addition, when 1 part by mass of thewater-soluble polymer (C-3) was dissolved in 100 parts by mass of water,its surface tension at 25° C. was 38 dyn/cm.

Example 6

Based on 100 parts by mass of a conductive polymer (A1-1) solution(conductive polymer: 8.8×10⁻³ mol), 17 parts by mass of a 5% solution of1,8-diazabicyclo[5.4.0]-7-undecene was added, and 0.06 parts by mass ofa water-soluble polymer (C-1) was further added. Accordingly, aconductive composition (1C) was obtained. Various measurements andevaluations were conducted on the conductive composition (1C). Theresults are shown in Table 5.

Example 7

Except that a 5% solution of 1,8-diazabicyclo[5.4.0]-7-undecene inexample 6 was replaced with 15 parts by mass of a solution of1,5-diazabicyclo[4.3.0]-5-nonene, conductive composition (2C) wasprepared the same as in example 6, and various measurements andevaluations were conducted. The results are shown in Table 5.

Example 8

Except that a 5% solution of 1,8-diazabicyclo[5.4.0]-7-undecene inexample 6 was replaced with 11 parts by mass of a 5% solution of4-dimethylaminopyridine, conductive composition (3C) was prepared thesame as in example 6, and various measurements and evaluations wereconducted. The results are shown in Table 5.

Example 9

Except that a 5% solution of 1,8-diazabicyclo[5.4.0]-7-undecene inexample 6 was replaced with 9 parts by mass of a 5% solution of4-dimethylaminopyridine, conductive composition (4C) was prepared thesame as in example 6, and various measurements and evaluations wereconducted. The results are shown in Table 5.

Example 10

Except that a 5% solution of 1,8-diazabicyclo[5.4.0]-7-undecene inexample 6 was replaced with 15 parts by mass of a 5% solution of4-dimethylaminopyridine, conductive composition (5C) was prepared thesame as in example 6, and various measurements and evaluations wereconducted. The results are shown in Table 5.

Example 11

Except that 15 parts by mass of a 5% solution of 4-dimethylaminopyridinein example 10 was changed to 17 parts by mass, conductive composition(6C) was prepared the same as in example 10, and various measurementsand evaluations were conducted. The results are shown in Table 5.

Example 12

Except that a 5% solution of 1,8-diazabicyclo[5.4.0]-7-undecene inexample 6 was replaced with 12 parts by mass of a 5% solution ofaminopyridine (AP), conductive composition (7C) was prepared the same asin example 6, and various measurements and evaluations were conducted.The results are shown in Table 5.

Comparative Example 5

Except that a 5% solution of 1,8-diazabicyclo[5.4.0]-7-undecene inexample 6 was not contained, conductive composition (8C) was preparedthe same as in example 1, and various measurements and evaluations wereconducted. The results are shown in Table 5.

Comparative Example 6

Except that a 5% solution of 1,8-diazabicyclo[5.4.0]-7-undecene inexample 6 was replaced with 10 parts by mass of a 5% solution ofpyridine (Py), conductive composition (9C) was prepared the same as inexample 6, and various measurements and evaluations were conducted. Theresults are shown in Table 5.

Comparative Example 7

Except that a 5% solution of 1,8-diazabicyclo[5.4.0]-7-undecene inexample 6 was replaced with 13 parts by mass of a 5% solution oftriethylamine (TEA), conductive composition (10C) was prepared the sameas in example 6, and various measurements and evaluations wereconducted. The results are shown in Table 5.

Comparative Example 8

Except that a 5% solution of 1,8-diazabicyclo[5.4.0]-7-undecene inexample 6 was replaced with 19 parts by mass of a 5% solution oftetraethyl ammonium compound (TEAH), conductive composition (11C) wasprepared the same as in example 6, and various measurements andevaluations were conducted. The results are shown in Table 5.

Comparative Example 9

Except that a 5% solution of 1,8-diazabicyclo[5.4.0]-7-undecene inexample 6 was replaced with 2 parts by mass of a 5% solution of ammonia(NH₃), conductive composition (12C) was prepared the same as in example6, and various measurements and evaluations were conducted. The resultsare shown in Table 5.

Comparative Example 10

Except that a 5% solution of 1,8-diazabicyclo[5.4.0]-7-undecene inexample 6 was replaced with 10 parts by mass of a 5% solution ofbis(2-dimethylaminoethylether) (BDAEE), conductive composition (13C) wasprepared the same as in example 6, and various measurements andevaluations were conducted. The results are shown in Table 5.

TABLE 5 example 6 example 7 example 8 example 9 example 10 example 11example 12 conductive composition 1C 2C 3C 4C 5C 6C 7C added base DBUDBN DMAP DMAP DMAP DMAP AP content of basic [mol %] 70 70 50 60 70 80 70compound (E1) surface resistance [Ω/□] 5.00E+08 5.00E+08 2.00E+071.00E+08 1.00E+08 9.00E+08 2.00E+07 reduction in [nm] 1 0 4 −1 0 −1 0film thickness comp. comp. comp. comp. comp. comp. example 5 example 6example 7 example 8 example 9 example 10 conductive composition 8C 9C10C 11C 12C 13C added base — Py TEA TEAH NH₃ BDAEE content of basic [mol%] — 70 70 70 70 70 compound (E1) surface resistance [Ω/□] — 2.00E+073.00E+08 5.00E+09 3.00E+06 — reduction in [nm] 205 71 6 3 72 — filmthickness

-   -   Abbreviations in Table 5 are as follows:        DBU: 1, 8-diazabicyclo[5.4.0]-7-undecene        DBN: 1,5-diazabicyclo[4.3.0]-5-nonene        DMAP: 4-dimethylaminopyridine        AP: aminopyridine        Py: pyridine        TEA: triethylamine        TEAH: tetracthylammonium compound        NH₃: ammonia        BDAEE: bis(2-dimethylaminoethylether)

As is clear in Table 5, examples 6 to 12 prepared by adding a basiccompound (E1) exhibited excellent conductivity (surface-resistance valueis low), and a reduction in the film thickness of the resist layer waslowered.

By contrast, comparative example 6 prepared using a conductivecomposition that does not contain a basic compound (D1) and comparativeexamples 7 to 10 prepared by using a basic compound other than the basiccompound (E1) showed a significant reduction in film thickness.

Comparative example 8 prepared by adding a basic compound other than thebasic compound (E1) showed a relatively small reduction in the filmthickness of the resist, but the conductivity of the conductive coatingfilm was insufficient.

From the results above, it is found that the conductive composition ofthe fourth embodiment exhibits excellent conductivity (surfaceresistance) and is capable of providing a conductive coating film thatis less likely to affect adversely the resist so as to lower a reductionin the film thickness of the resist.

Next, examples of the conductive compositions according to the fifth andsixth embodiments of the present invention are described.

(Evaluation of Coating Performance)

Chemically amplified electron-beam resist was spin-coated (2000 rpm×60seconds) on a 4-inch silicon wafer (hereinafter referred to as a siliconsubstrate), and heat was applied on a hot plate at 130° C. for 90seconds to form a resist layer on the 4-inch silicon wafer. On theresist layer, the conductive composition according to the fifth or sixthembodiment was spin-coated (2000 rpm×60 seconds). The surface conditionwas visually observed and the coating performance was evaluatedaccording to the following evaluation criteria.

A: no repelling was observed on the surface.

B: repelling was observed on part of the surface.

C: significant repelling was observed.

<Evaluation of Conductivity>

The same method described in the examples of the third embodiment wasemployed to evaluate conductivity.

<Surface Roughness>

The same method described in the examples of the third embodiment wasemployed to measure surface roughness (Ra1 value and Ra2 value).

<Reduction in Film Thickness>

The same method described in the examples of the third embodiment wasemployed to measure the reduction in the film thickness of the resist.

Using the conductive polymer (A-1) obtained in production example 1A andthe water-soluble polymer (C-3) obtained in production example 8A,conductive compositions were prepared as follows.

Examples 13 to 15, Comparative Example 11, 12

To 100 parts by mass of a conductive polymer (A1-1) solution (conductivepolymer: 8.8×10⁻³ mol), a basic compound was added to prepare aconductive composition. The type and content of the basic compound areshown in Table 6. For each of the obtained conductive compositions,surface resistance was measured, coating performance was evaluated, anda reduction in the film thickness of the resist layer was measured. Theresults are shown in Table 6.

Example 16

To 100 parts by mass of a conductive polymer solution (A1-1) (conductivepolymer: 8.8×10⁻³ mol), 27 parts by mass of a 5% tetrabutylammoniumhydroxide solution (TBAH) as a basic compound (E2) and 0.18 parts bymass of a water-soluble polymer (C-3) were added to prepare conductivecomposition (4D).

The surface resistance, coating performance and reduction in the filmthickness of the resist layer of the obtained conductive compositionwere measured. The results are shown in Table 6.

Example 17

Conductive composition (5D) was prepared by the same procedure as inexample 16 except that TBAH in example 16 was replaced with 21 parts bymass of a 5% solution of tetrapropylammonium hydroxide (TPAH).

The surface resistance, coating performance and reduction in the filmthickness of the resist layer of the obtained conductive composition(5D) were measured. The results are shown in Table 6.

Example 18

To 100 parts by mass of a conductive polymer solution (A1-1) (conductivepolymer: 8.8×10⁻³ mol), 13 parts by mass oftris(hydroxymethyl)aminomethane (Tris) as a basic compound (E3) and 0.18parts by mass of a water-soluble polymer (C-3) were added to prepareconductive composition (6D).

The surface resistance and reduction in the film thickness of the resistlayer of the obtained conductive composition (6D) were measured. Theresults are shown in Table 6.

Examples 19, 20, Comparative Examples 15 to 19

Conductive compositions were each prepared the same as in example 18except that the type and content of a basic compound (E3) wererespectively changed as shown in Table 6. The surface resistance,coating performance and reduction in the film thickness of the resistlayer were measured for each conductive composition. The results areshown in Table 6.

Comparative Example 13

To 100 parts by mass of a conductive polymer solution (A1-1) (conductivepolymer: 8.8×10⁻³ mol), 9 parts by mass of TPAH (5% solution) as a basiccompound (E2) were added to prepare conductive composition (11D).

The surface resistance, coating performance and reduction in the filmthickness of the resist layer of the obtained conductive composition(11D) were measured. The results are shown in Table 6.

Comparative Example 14

To 100 parts by mass of a conductive polymer solution (A1-1) (conductivepolymer: 8.8×10⁻³ mol), 15 parts by mass of TEAH (5% solution) as abasic compound (E2) were added to prepare conductive composition (12D).

The surface resistance, coating performance and reduction in the filmthickness of the resist layer of the obtained conductive composition(12D) were measured. The results are shown in Table 6.

TABLE 6 content presence reduction of of in basic water- surface filmconductive basic compound soluble resistance coating thicknesscomposition compound [mol %] polymer [Ω/□] performance [nm] example 131D TBAH 60 no 2.00E+09 A 3 example 14 2D TBAH 70 no 4.00E+10 A 2 example15 3D TBAH 70 no 5.80E+09 A 3 example 16 4D TBAH 60 yes 8.00E+09 A 2example 17 5D TPAH 60 yes 5.90E+09 A 2 example 18 6D Tris 60 yes1.50E+09 A 2 example 19 7D Tris 70 yes 6.50E+09 A 1 example 20 8D Tris80 yes 5.50E+10 A 1 comp. example 11 9D TMAH 70 no no data C no datacomp. example 12 10D TEAH 70 no no data C no data comp. example 13 11DTMAH 60 yes 1.30E+09 A 4 comp. example 14 12D TEAH 60 yes 3.60E+09 A 4comp. example 15 13D Tris 30 yes 7.60E+07 A 6 comp. example 16 14D Tris50 yes 3.20E+08 A 4 comp. example 17 15D Py 60 yes 2.00E+07 A 4 comp.example 18 16D TEA 60 yes 1.60E+08 A 5 comp. example 19 17D NH₃ 60 yes1.00E+07 A 4

-   -   Abbreviations in Table 6 indicate the following:        TBAH: tetrabutylammonium hydroxide,        TPAH: tetrapropylammonium hydroxide,        TEAH: tetraethylammonium hydroxide,        TMAH: tetramethylammonium hydroxide,        DBN: 1,5-diazabicyclo[4.3.0]-5-nonene,        Tris: tris(hydroxymethyl)aminomethane,        Py: pyridine,        TEA: triethylamine,        NH₃: ammonia

In Table 6, “content of base” indicates the content of a basic compound(mol equivalent) based on 1 mol of a unit having an acidic group amongthe monomers of the conductive polymer.

As is clear from Table 6, conductive compositions (1D to 3D) of examples13 to 15 each prepared by adding a basic compound (E2) exhibitedexcellent coating performance on the resist layer and high conductivity.

By contrast, conductive compositions (9D) and (10D) of comparativeexamples 11 and 12 each prepared by adding a quaternary ammoniumcompound in which four groups bonded to a nitrogen atom are each analkyl group having 2 or fewer carbon atoms, showed low coatingperformance. Namely, it was found difficult to form a conductive coatingfilm on the resist layer by using the conductive compositions ofcomparative examples 11 and 12. Thus, evaluation by film reductiontesting was not conducted on comparative examples 11 and 12.

As is clear from Table 6, the conductive compositions of the examples,each prepared by adding a basic compound (E2) or basic compound (E3),showed that acidic substances had caused less reduction (f) in the filmthickness of the resist layer.

By contrast, using conductive compositions (13D, 14D) of comparativeexamples 15 and 16 containing a small amount of a basic compound (E3),and conductive compositions (16D, 17D) of comparative examples 18 and 19prepared by using TEA or NH₃ as a basic compound, the reduction in thefilm thickness of the resist layer, caused by acidic substances, wassignificant.

INDUSTRIAL APPLICABILITY

An embodiment of the present invention provides a conductor whichexhibits less reduction in the film thickness of the resist layer andexcellent surface roughness applicable to a next-generation process forsemiconductor devices. Another embodiment of the present inventionprovides a conductive composition containing a surfactant capable ofreducing clogging of a filter used for filtration of the conductivecomposition. Another embodiment of the present invention provides aconductive composition capable of forming a conductive coating film thathas less adverse impact on the substrate and exhibits excellent surfaceroughness. Also, another embodiment of the present invention provides aconductive composition that exhibits excellent conductivity (surfaceresistance) and less reduction in the film thickness. Furthermore,another embodiment of the present invention provides a conductivecomposition capable of forming a conductive coating film that has lessadverse impact on the resist layer.

1. A conductor comprising: a substrate and a conductive coating filmlaminated on the substrate, wherein a surface resistance value of theconductive coating film is 5×10¹⁰Ω/□ or less, a surface roughness (Ra1value) of the conductive coating film measured by a stylus profiler is0.7 nm or less, a surface roughness (Ra2 value) of the conductivecoating film measured by a scanning probe microscope is 0.35 nm or less,and the conductive coating film is formed with a conductive compositioncomprising a conductive polymer (A).
 2. The conductor according to claim1, wherein the conductive polymer (A) has an acidic group.
 3. Theconductor according to claim 2, wherein the acidic group is at least oneselected from the group consisting of a sulfonic acid group and acarboxyl group.
 4. The conductor according to claim 1, wherein theconductive polymer (A) has a monomer unit represented by formula (1)

wherein R¹ to R⁴ each independently represents a hydrogen atom, astraight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom, and at least one of R¹ to R⁴ represents an acidic group orsalt thereof.
 5. A conductive composition comprising a conductivepolymer (A) and a surfactant (B), wherein the surfactant (B) has awater-soluble polymer (C) having a nitrogen-comprising functional groupand a terminal hydrophobic group, and a content of a compound (D1) withan octanol-water partition coefficient (Log Pow) of 4 or more in theconductive composition is 0.001 mass % or less, relative to the totalmass of the conductive composition.
 6. The conductive compositionaccording to claim 5, wherein the water-soluble polymer (C) has anitrogen-comprising functional group and a terminal hydrophobic groupand with a weight-average molecular weight of 2000 or more.
 7. Theconductive composition according to claim 6, wherein the water-solublepolymer (C) comprises a vinyl monomer unit having a nitrogen-comprisingfunctional group in the molecule.
 8. The conductive compositionaccording to claim 5, wherein the conductive polymer (A) has a monomerunit represented by formula (1)

wherein R¹ to R⁴ each independently represents a hydrogen atom, astraight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom, and at least one of R¹ to R⁴ represents an acidic group orsalt thereof.
 9. The conductive composition according to claim 5,wherein the conductive polymer (A) has at least one acidic groupselected from the group consisting of a sulfonic acid group and acarboxyl group.
 10. A conductive composition comprising a conductivepolymer (A1) and a basic compound (E1), wherein the basic compound (E1)has a conjugated structure and two or more tertiary amines in themolecule.
 11. The conductive composition according to claim 10, whereinthe conductive polymer (A1) has a monomer unit represented by formula(1)

wherein R¹ to R⁴ each independently represents a hydrogen atom, astraight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom, and at least one of R¹ to R⁴ represents an acidic group orsalt thereof.
 12. The conductive composition according to claim 10,wherein the conductive polymer (A1) has at least one acidic groupselected from the group consisting of a sulfonic acid group and acarboxyl group.
 13. A conductive composition comprising a conductivepolymer (A) and a basic compound (E2), wherein the basic compound (E2)is a quaternary ammonium salt in which at least one of four groupsbonded to a nitrogen atom is an alkyl group having 3 or more carbonatoms.
 14. The conductive composition according to claim 13, wherein theconductive polymer (A) has a monomer unit represented by formula (1)

wherein R¹ to R⁴ each independently represents a hydrogen atom, astraight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom, and at least one of R¹ to R⁴ represents an acidic group orsalt thereof.
 15. The conductive composition according to claim 13,wherein the conductive polymer (A) has at least one acidic groupselected from the group consisting of a sulfonic acid group and acarboxyl group.
 16. A conductive composition comprising a conductivepolymer (A) and a basic compound (E3), wherein the conductive polymer(A) comprises a monomer unit having an acidic group, the basic compound(E3) has a basic group and two or more hydroxyl groups in the molecule,and a melting point of 30° C. or more, and a content of the basiccompound (E3) in the conductive composition is 0.6 to 0.8 mol, relativeto 1 mol of the monomer unit having an acidic group of the conductivepolymer (A).
 17. The conductive composition according to claim 16,wherein the monomer unit having an acidic group in the conductivepolymer (A) is represented by formula (1)

wherein R¹ to R⁴ each independently represents a hydrogen atom, astraight-chain or branched-chain alkyl group having 1 to 24 carbonatoms, a straight-chain or branched-chain alkoxyl group having 1 to 24carbon atoms, an acidic group, a hydroxyl group, a nitro group or ahalogen atom, and at least one of R¹ to R⁴ represents an acidic group orsalt thereof.
 18. The conductive composition according to claim 16,wherein the acidic group is at least one selected from the groupconsisting of a sulfonic acid group and a carboxyl group.
 19. Theconductive composition according to claim 10, further comprising asurfactant (B).
 20. The conductive composition according to claim 19,wherein the surfactant (B) comprises a water-soluble polymer (C) havinga nitrogen-comprising functional group and a terminal hydrophobic group,and a content of a compound (D1) with an octanol-water partitioncoefficient (Log Pow) of 4 or more in the conductive composition is0.001 mass % or less, relative to the total mass of the conductivecomposition.
 21. A laminate comprising a substrate, a conductive coatingfilm and an electron-beam resist film, wherein the electron-beam resistfilm is laminated on at least one surface of the substrate, theconductive coating film is laminated on the electron-beam resist film; asurface resistance value of the conductive coating film is 5×10¹⁰Ω/□ orless, a surface roughness (Ra1 value) of the conductive coating filmmeasured by a stylus profiler is 0.7 nm or less, a surface roughness(Ra2 value) of the conductive coating film measured by a scanning probemicroscope is 0.35 nm or less, and the conductive coating film is formedusing a conductive composition comprising a conductive polymer (A).